Tic Tac Toe Multiplayer in Zig

A multiplayer Tic Tac Toe game built to learn the Zig programming language.

Educational Purpose

This project was created for educational purposes to learn:

• Zig programming language fundamentals
• TCP socket networking
• State management
• Modularity

What we have

• Local Play: Two players on the same computer
• Network Multiplayer: Host or join games over TCP
• Real-time Synchronization: Instant move updates between players
• Cross-platform: Works on macOS, Linux, and Windows

Technologies Used

• Zig - A general-purpose programming language and toolchain
• Raylib - A simple and easy-to-use library for game development
• raylib-zig - Zig bindings for Raylib

Prerequisites

• Zig 0.14.0 or later
• Git

Getting Started

1. Clone the repository:

git clone https://github.com/yourusername/learn-zig.git
cd learn-zig

1. Build the project:

zig build

1. Run the game:

zig build run

How to Play

Local Play

1. Launch the game and select "Local Play"
2. Players take turns clicking on the grid
3. First player to get 3 in a row wins

Network Multiplayer

To host a game:

1. Select "Host Game" from the main menu
2. Note the port number (default: 5555)
3. Share your IP address with the other player
4. Wait for them to connect

To join a game:

1. Select "Join Game" from the main menu
2. Enter the host's IP address
3. Enter the port number (default: 5555)
4. Click "Connect"

Game Rules:

• The host plays as X and goes first
• The client plays as O
• Players take turns clicking empty squares
• First to get 3 in a row wins

Project Structure

src/
├── main.zig         # Entry point and game loop
├── game.zig         # Game logic and state management
├── renderer.zig     # All drawing and UI rendering
├── network.zig      # TCP networking implementation
├── ui_state.zig     # UI state definitions
├── input.zig        # Input handling utilities
└── constants.zig    # Shared constants and configuration

Building from Source

The project uses Zig's built-in build system. The build.zig file configures:

• Executable compilation
• Raylib dependency linking
• Build options and flags

To build in release mode for better performance:

zig build -Doptimize=ReleaseFast

Network Protocol

The multiplayer mode uses a simple TCP protocol with message types:

• CONNECT - Initial handshake
• MOVE - Transmit player moves
• RESET - Restart the game
• DISCONNECT - Clean disconnection

Messages are serialized with a 4-byte header indicating message length.

Learning Resources

For those learning Zig:

• Zig Language Documentation
• Ziglearn
• Zig by Example

For Raylib:

• Raylib Cheatsheet
• Raylib Examples

Acknowledgments

• The Zig community for excellent documentation
• Raylib
• raylib-zig for the Zig bindings of the Raylib