Dao-net

An application-layer protocol to bring order to P2P multiplayer games

Inspired by League of Legend's game clock synchronisation, this project aims to build an application-layer protocol that mitigates the propagation of erroneous game states due to network delay in a P2P, latency-averse multiplayer game by synchronising game clock.

This project was done for SUTD's 50.021: Networks module. The aim of the project is to propose a specific problem related to networks application, protocol or architecture.

Project Structure

• Game
  • Clock
    • clock.py
    • delay.py
    • sync.py
  • Lobby
    • lobby.py
    • tracker.py
  • Models
    • player.py
  • Transport
    • packet.py
    • transport.py
• client.py
• thread_manager.py
• logs

Features

The two main issues of a P2P game are network delay and game state consensus.

Thus, we have designed a two-pronged approach:

1. Latency Aware Propagation
2. Frame Syncing

In addition, we have implemented a P2P version of musical chairs known as QWERTYchairs to test our solution.

Project Architecture

Getting Started

1. Git clone the repository

git clone https://github.com/rphly/dao-net.git

2. Open up the root directory and install the dependencies

pip install -r requirements.txt

Running the Game

A minimum of two players are required to play the game.

1. On one machine, set up a host lobby with the commands:

a) MacOs

clear && sudo -E ./env/bin/python main.py -m host -ip <your_ip_address> -hp <port_number>

b) Windows

python main.py -m host -ip localhost -hp 9999

On a successful host startup, the host should see the message:

Starting host mode on port 9999.

Whenever another player has joined the lobby, the host should see:

Player registered: vital-boar
Current players: ['tough-hyena', 'vital-boar']

2. On another machine, enter the lobby as a player using:

a) MacOs

clear && sudo -E ./env/bin/python main.py -ip <host_ip_address> -hp <host_port_number> -pip <your_ip_address> -pp <port_number>

b) Windows

python main.py -ip <host_ip_address> -hp <host_port_number> -pip <your_ip_address> -pp <port_number>

On a successful player startup, the player should see the message:

Starting in player mode.

3. The host will be updated when players join the lobby:

Current players: ['tough-hyena']
Player registered: vital-boar
Current players: ['tough-hyena', 'vital-boar']

4. When there are sufficient players (more than 1), the host can start the game by pressing theSPACEBAR key.

All clients notified of game start.
Exiting lobby, entering game

How to Play QWERTYchairs

Selecting Seats

When synchronisation is done, the game will begin counting down. When the countdown finishes, the round will start and players will be prompted to "take a seat" by pressing on one of the keys "Q","W","E","R","T", or "Y".

|-------- ROUND 1 --------|
[PLAYING AS] vital-boar
[CURRENT PLAYERS] ['vital-boar', 'tough-hyena']
[AVAILABLE SEATS] {'Q': None}
[SYSTEM] GRAB A SEAT NOW !!!

If the player manages to successfully take that seat i.e. no one else has taken that seat before the player, he will see:

[ACTION] I HAVE PRESSED Q
[ACTION] I have sat down successfully!
[SEATS] {'Q': 'vital-boar'}

If the player has failed to take a seat, he will see:

[ACTION] I HAVE PRESSED Q
[ACTION] Failed to sit down, pick a new seat!

When another player has taken a seat, he will see a prompt:

[ACTION] vital-boar has sat down!
[SEATS] {'Q': 'vital-boar'}

Determining the loser of the round

When the seats are filled, players will hold a vote to kick the player who has failed to find a seat on their records. When all votes are in, the player will be moved into a spectator state.

[VOTE] Voting to kick: tough-hyena
[SYSTEM] Received vote to kick tough-hyena

 ---- ALL VOTES IN ----
[KICKING LOSER] Kicking player: tough-hyena

Round End

The game continues until there is one player left, after which the game will terminate.

---- Round has ended. Players left: ['vital-boar'] ----
[SYSTEM] Reducing number of chairs...
[SYSTEM] No more seats left, game over.

--- Congrats! You have won the game! ---

Hope you had fun!

Visualising the Test Results for Frame Syncing

The results of the game will automatically be logged. These logs will be stored in the ./logs folder, shift all the log files for relevant game to the ./logs_parse folder.

To see the test results for frame syncing in a chart, key in the command:

python visualizations.py

Additional Resources

Project Report: https://docs.google.com/document/d/1M1x-pMdd0eYDzquYMMAF3uyoVvAy0XSJtn3hpExUnaA/edit#

Final Presentation: https://docs.google.com/presentation/d/1FkBAM7jufYnY1UtCDipZn64lYQgso2DqmwFn6kiv5KM/edit#slide=id.g22c0e6bf17b_0_629