PolyCore

A Simple and Small Multiplayer Tetris Server in Java using WebSockets

Warning

This Project is currently in early development and is not yet ready for production use. The core server functionality is being built, but many features are still in progress. Stay tuned for updates!

📖 Overview

PolyCore is a lightweight, real-time multiplayer Tetris server built with Java and WebSockets. It allows multiple players to connect, create or join game rooms, and compete against each other in classic Tetris gameplay.

✨ Features

• 🎯 Real-time Multiplayer - Play Tetris with friends in real-time
• 🏠 Room System - Create and join game rooms with configurable player limits
• 💬 In-game Chat - Communicate with other players via chat
• 🔧 Command System - Execute commands via chat (prefix with /)
• ⚙️ Configurable - Flexible YAML-based configuration
• 🔌 Extensible Packet System - Easy-to-extend annotation-based packet handling
• 🎮 Full Tetris Mechanics - Rotation, hold piece, hard drop, line clearing, and more

Clients

Currently, there is only one very basic example client (Written with Github Co-Pilot)

However, you can create your own client using any WebSocket library that follows the packet structure defined in the documentation below.

I do plan on creating a simple web-based client in the future (or even a Java-based one), as soon as the Server is working as intended.

• Example Client
  • A very simple example Client written in HTML and JavaScript, which can be used as a base for your own client or just to test the server functionality.
    (Used for initial testing, written by Copilot)

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🚀 Getting Started

Installation

TODO

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⚙️ Configuration

On first run, a config.yml file will be created. Here are the available options:

application:
  host: 0.0.0.0       # Bind address (0.0.0.0 for all interfaces)
  port: 3091          # Server port

# Some other settings
# which will not work yet, but will be implemented in the future.

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📡 WebSocket API

Connection

Connect to the server via WebSocket:

ws://<host>:<port>/tetris/game

Packet Format

All packets follow this JSON structure:

{
  "type": "PACKET_TYPE",
  "payload": { ... }
}

Available Packets

Client → Server

Packet Type	Payload	Description
AUTH	{"username": "string"}	Authenticate with the server (required first)
CREATE_ROOM	{"room_name": "string", "max_players": int}	Create a new game room
JOIN_ROOM	{"room_id": "string"}	Join an existing room
SHOW_ROOMS	/	List all available rooms
CHAT	{"content": "string"}	Send a chat message or command
PING	any	Ping the server
LEFT	-	Move piece left
RIGHT	-	Move piece right
DOWN	-	Soft drop piece
DROP	-	Hard drop piece
ROTATE	-	Rotate piece
HOLD	-	Hold current piece

Server → Client

Packet Type	Payload	Description
AUTH_SUCCESS	{"message": "...", "username": "..."}	Authentication successful
AUTH_ERROR	string	Authentication failed
CREATE_SUCCESS	string (room_id)	Room created successfully
JOIN_SUCCESS	{"room_id": "...", "currentPlayers": int, "maxPlayers": int}	Joined room successfully
SHOW_ROOMS	{"rooms": [...]}	List of available rooms
UPDATE	{"states": {...}}	Game state update
START	string	Game started
DEATH	string (player_name)	Player died
WINNER	string (player_name)	Game winner
JOIN	string (player_name)	Player joined room
LEAVE	string (player_id)	Player left room
MESSAGE	{"text": "...", "raw": "..."}	Chat message
PONG	any	Ping response

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🎮 Game Controls

Once in a game room, send these packet types (no payload needed) to control your piece:

Action	Packet Type
Move Left	LEFT
Move Right	RIGHT
Soft Drop	DOWN
Hard Drop	DROP
Rotate	ROTATE
Hold Piece	HOLD

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💬 Commands

Commands are sent via the CHAT packet with content prefixed by /:

Command	Description
/help	Show available commands
/stop	Stop the server (admin only)
/start	Start the game in current room

More to follow!

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🛠️ Tech Stack

• Java 21 - Modern Java features
• Maven - Build and dependency management
• Jakarta WebSocket API - WebSocket standard
• Tyrus - WebSocket server implementation (Grizzly container)
• Gson - JSON serialization
• BoostedYAML - YAML configuration
• Reflections - Runtime annotation scanning

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📝 License

This project is licensed under the MIT License - see the LICENSE file for details.

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👤 Author

JoshiCodes (aka Joroshi)

• GitHub: @JoshiCodes

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🤝 Contributing

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

1. Fork the project
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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Made with ❤️ and ☕ by JoshiCodes
Logo SVG by Neuicons from svgrepo.com