Introduction

TetriQ is a multiplayer tetris game.

This manual documents how to use and configure the game's server and client as well as the underlying network protocol and technical details.

Current version: 4.1


Copyright © 2024 The TetriQ authors.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

Usage

Launch client

./tetriq_client <ip> <port> <displayMode>

ip: IP adress of the server (IPv4)

port: Port of the server

displayMode: Choose between sfml or ncurses

Ncurses Keybinds

Left Arrow: Move left

Right Arrow: Move right

Down Arrow: Move down

Up Arrow: Rotate

Space: Drop

Q: Send powerup

S: Target player

0-9: Target player id (need "select target mode": S)

Z: Target next player

X: Target previous player

Note that when targeting players with S, on press you have a 2 seconds delay to enter a player ID (1 - 999) refreshed every time you add a digit. Press any non-numerical key or wait the 2 seconds to save the target ID.

SFML Keybinds

Left Arrow: Move left

Right Arrow: Move right

Down Arrow: Move down

Up Arrow: Rotate

Space: Drop

Q: Send powerup

shift (hold): Select target mode

0-9: Target player id (need "select target mode": shift)

h: Show help

esc: Exit game

Note that when targeting players with shift (hold), you can type the player ID. Press shift again to reset the target to 0 (self). e.g. shift (hold) + 1 + 2 + 3 will target player 123.

RCON usage

The Remote Console (RCON) is a feature that allows you to send commands to a running TetriQ server.

Enabling RCON

To enable RCON, you need to set the enabled field in the rcon section of the configuration file to true.

Connecting to the RCON server

You can connect to the RCON server using netcat or a similar tool. The default port is 31458.

$ nc localhost 31458

Authenticating

To authenticate, you need to send the password set in the configuration file as your first command.

Sending commands

After authenticating, you can send commands to the server. Commands are sent as a single line of text. Here a list of available commands:

  • help: Display a list of available commands.
  • quit: Disconnect from the RCON server.
  • set channel <id>: This command is a bit special. Our TetriQ server uses "channels" to separate different games. You can set the channel you want to send commands to by using this command. For example, set channel 0 will set the current selected channel to channel 0.
  • list: List all channels by displaying the number of players in each channel and an indicator if the game is running or not.
  • create channel: Create a new channel. (kind of useless, because players can't join a specific channel for now).
  • delete channel <id>: Delete a channel. id being the channel ID.
  • get: not implemented yet.
  • startgame: Start a game in the current channel.
  • stopgame: Stop the game in the current channel.

Building from source

You can download the source code from github: https://github.com/TetriQ/TetriQ

Dependencies

To build TetriQ, you will need the following dependencies:

  • CMake
  • ENet
  • tomlplusplus

Additionally for the client:

  • SFML
  • ncurses

Building

TetriQ uses the CMake build system, you can easily compile the code with the following commands:

cmake -B build -S . -DCMAKE_BUILD_TYPE=Release
cmake --build build/ -j

You will then find the server and client binaries under the names tetriq_server and tetriq_client in your current directory.

Installing

You can install TetriQ using cmake:

cmake --install build

You will need to copy the two config files in the etc/ directory to a directory searched by TetriQ (see Server configuration).

Nonstandard directory

You can use the CMake variable TETRIQ_CONFIG_PATH to specify the directory where you installed the two config files. For example, if you installed them in /usr/local/etc/tetriq:

cmake -B build -S . -DCMAKE_BUILD_TYPE=Release -DTETRIQ_CONFIG_PATH=/usr/local/etc/tetriq

Server configuration

If you want to run your own server, all you will need is a valid configuration file! The format of the file and the available configurations are documented in this section.

When the server is started using tetriq_server, it will look for configuration files in the following locations in order until it finds a valid one:

  1. server.toml
  2. etc/server.toml
  3. $XDG_CONFIG_HOME/tetriq/server.toml
  4. /etc/tetriq/server.toml

In the case that XDG_CONFIG_HOME is not set, it will default to ~/.config.

To make your own configuration, copy the configuration file that should be distributed along with TetriQ at either etc/server.toml or /etc/tetriq/server.toml to one of the directories listed above (three or four is preferable) and modify it as you see best.

Configuration fields

Here are the available configuration fields, along with their default value and description. If any field is missing from the configuration file, its default value will be used.

  • max_clients = 128

The maximum amount of open connections that can be made to the server. This will directly impact RAM usage by ENet1, no matter how many players are actually connected.

  • max_outgoing_bandwidth = 0

Upstream bandwidth of the host in bytes/second; if 0, ENet1 will assume unlimited bandwidth.

  • max_incoming_bandwidth = 0

Downstream bandwidth of the host in bytes/second; if 0, ENet1 will assume unlimited bandwidth.

1

ENet is the network library used by TetriQ to manage connections.

  • client_timeout = 1000

The time in milliseconds for a client to timeout. This is currently unused and does nothing.

  • listen_address = "0.0.0.0"

The address on which the server will listen for incoming connections. Make sure to set this to an address that is reachable by your peers. Here are a few example values:

AddressUsage
127.0.0.1The loopback address. Will only accept connections from your computer
0.0.0.0Special. Will accept connections on any address
192.0.0.20Local ip address. Will accept connections from your local network. Yours will probably have a different value

When connecting with a client, make sure the address you use matches the one you chose for your server.

  • listen_port = 31457

The port on which the server will listen for incoming connections.

  • ticks_per_second = 60

The frequency at which the server updates its internal state. This is different than ticks_per_second in the [game] section which is the speed for the game itself.

Make sure that this is greater than the game's ticks_per_second or else the game will be running slower than expected. Setting this too high will increase resource consumption for very few latency gains.

Game configuration

The game rules can be configured in the [game] section of the server's configuration file. Here are the available configuration fields, along with their default value and description. If any field is missing from the configuration file, its default value will be used.

  • ticks_per_second = 5

The frequency at which the game is updated, i.e. the number of times per second blocks fall down.

  • width = 12

The width of the game area in blocks. This includes the game's unbreakable border.

  • height = 22

The height of the game area in blocks. This includes the game's unbreakable border.

RCON configuration

The server can be controlled remotely using the RCON protocol. The RCON is using simple TCP sockets. This means that you can use telnet or netcat to connect to the RCON server and send commands to it.

Notes:

  • every command must be terminated by a newline character. Beware telnet users.
  • for now, the RCON is not secured. It is recommended to use a firewall to restrict access to the RCON port.
  • the RCON is also not encrypted. It uses plain text.
  • there can be only one RCON connection at a time.

The RCON configuration can be found in the [rcon] section of the server's configuration file. Here are the available configuration fields, along with their default value and description. If any field is missing from the configuration file, its default value will be used.

  • enabled = true

Whether the RCON server is enabled or not.

  • password = "root"

The password required to authenticate with the RCON server. It's the first thing you should change when enabling the RCON server.

  • listen_address = "0.0.0.0"

The address on which the RCON server will listen for incoming connections.

  • listen_port = 31458

The port on which the RCON server will listen for incoming connections (TCP)

Client configuration

The client can also be configured, when it is started, it will look for a configuration file in the following locations in order until it finds a valid one:

  1. client.toml
  2. etc/client.toml
  3. $XDG_CONFIG_HOME/tetriq/client.toml
  4. /etc/tetriq/client.toml

In the case that XDG_CONFIG_HOME is not set, it will default to ~/.config.

To make your own configuration, copy the configuration file that should be distributed along with TetriQ at either etc/client.toml or /etc/tetriq/client.toml to one of the directories listed above (three or four is preferable) and modify it as you see best.

Configuration fields

Here are the available configuration fields, along with their default value and description. If any field is missing from the configuration file, its default value will be used.

  • max_outgoing_bandwidth = 0

Upstream bandwidth of the host in bytes/second; if 0, ENet1 will assume unlimited bandwidth.

  • max_incoming_bandwidth = 0

Downstream bandwidth of the host in bytes/second; if 0, ENet1 will assume unlimited bandwidth.

  • server_timeout = 1000

The maximum time in milliseconds to wait for the server's answer during connection.

1

ENet is the network library used by TetriQ to manage connections.

Protocol

The TetriQ network protocol uses a client-server architecture. It is designed to prevent obvious cheating while still being playable on high latency and low bandwidths connections. For this, the server sends frequent incremental updates to the client, and the client keeps an internal prediction of the game state.

Starting games

Initially, clients connected to the server have no game running. To start the game, the server sends to the client an InitGamePacket containing the information needed to prepare the game board, followed by a FullGamePacket to synchronise its contents.

Game loop

The game loop is led by the server. At the tick speed of the game, it will collect all actions received from players and apply them to their boards. Once done, the server sends a TickGamePacket event to players, containing the number of actions applied so that the clients can update their internal state.

From the clients' side, the player actions are sent to the server as they happen in GameActionPackets, and the internal state is updated without waiting for the server's response. Once the TickGamePacket is received, the client rolls back its internal state to the server's and reapplies any unhandled actions.

In case of a synchronisation issue, the client can send a FullGameRequestPacket which will cause the server to send a new FullGamePacket containing the whole board.

For showing the other player's boards, the server broadcasts a FullGamePacket every time the board is meaningfully changed (for example when a block is placed).

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