ABx

Ancient Greece Multiplayer Online RPG.

https://devtube.dev-wiki.de/video-channels/trill_channel/videos

https://www.gamedev.net/projects/1587-abx

License

The source code is licensed under the MIT License.

Assets, Data, Art made by me is licensed under the CC BY 4.0.

ETA

Christmas 2117 +/- some years.

The Goals

• Instanced world
• Primary and secondary professions (classes)
• Big skill pool
• Diverse skill builds and team builds
• Focus on tactics rather than kill everything that moves
• Cooperative and competitive game formats
• PvP and PvE

Current features

• Uses a single TCP stream for the game protocol. This is not a shooter or action game, more like a classical online RPG.
• Database back-end is currently PostgreSQL.
• Instanced world.
• Encrypted Game and Login Protocol.
• Lag compensation: Client prediction.
• Network traffic compression:
  • Delta compression (send only state changes)
  • Send only relevant messages to each player, e.g. a Player doesn't need to know when an Actor moves far away from the Player
• The system is designed to scale:
  • It can spawn any number of server which may have heavy load (game, file server) even on different hardware.
  • Automatically spawn File and Game Server when needed.
• Chat system even across different game server:
  • Local (map) chat
  • Guild chat
  • Team chat
  • Trade chat
  • Whisper
• Friend/ignore list
• Persistent Mail
• Static objects are directly loaded from Urho3D's scene files.
• Lua API to script Games, NPCs, Skills, Effects, Items etc.
• Navigation using Recast/Detour
• Server runs on Windows and Linux
• Client runs on Windows and Linux
• Game AI, Behavior Tree
• Mumble voice chat integration with extended support (Context, identity, overlay), which provides spatial voice chat, see Positional-Audio.
• Item system:
  • Item drops, when foes are killed they may or may not drop a random item. Each Item has a certain drop chance on a certain map.
  • Player inventory and account chest (account wide storage).
  • Players can exchange Items and Money with other Players.
  • Players can sell items that dropped or otherwise obtained to a Merchant and gain money.
  • Players can buy items from the Merchant which the Merchant has in stock.
  • Dynamic item price taking availability and drop chance into account.
  • Players can craft new items for Materials and Money from special NPCs.
• Autoupdate asset files: It downloads only the differences and patches existing files. This greatly reduces time and bandwidth.
• Minimap, a small map of the scene the player is in, which also shows other actors.
• Class system with primary and secondary class. The player has a fixed primary class and a changeable secondary class.
• Skill system. Depending on the primary and secondary class of the player, different skills are available to the player.
• Skills are implemented a simple Lua scripts and can be added/removed/changed quickly.

Screenshot

Motivation

The only Computer Game I play is Guild Wars and I play it for well over 12 years now. With my main account I played for over 12,000 hours, and I still enjoy it. But the game is old, and does not get much love anymore. So maybe it's time to create something like it.

However, the main motivation for me is, I think Guild Wars is an awesome piece of technology, and I want to know if I can create something like it. I know the Art work is beyond my Art skills (they are literally not existent), but with enough time it should be possible to do the programming part.

There are some other nice side effects. It's exciting times to program in C++, it is moving fast, but does not break things.

Build, install, run

See BUILD.md and INSTALL.md.

FAQ

Q Some models appear (partly) transparent/invisible.

A This is a known issue (https://github.com/stievie/ABx/issues/75), see here https://github.com/stievie/ABx/issues/55 for a solution.

Contributing

Contributions are welcome! See CONTRIBUTING.md for more informations.

Credits

See CREDITS.md.

Architecture

Data Server

The Data server provides data from the database server and caches it. It also acts as threadsafe interserver shared memory. Connection to this server is required for:

• File Server
• Login Server
• Game Server

There can be only one data server. It is the central point to which all other servers connect, and get their data from.

File Server

The file server is a simple HTTP server providing files and other information. The client may connect to it from time to time and download data.

It is also used to update the game client and the client assets.

There can be any number of file servers. Usually you may want to have file servers in different regions, and not on the same machine. A file server does not need much resources, just bandwidth. But if they run on the same machine, they must listen on different ports.

Login Server

Used by the client to login, create accounts and manage characters.

It also tells the client to which Game and File Server to connect.

There can be only one login server, since all clients connect to this server. Once the client is authenticated, the connection to the login server is closed.

Game Server

The game server simulates the games. There can be any number of game servers, but if they run on the same machine, the game servers must listen on different ports.

Since all game server connect to the same data server, all game server share the same data. Because this game is designed to have an instanced world, several game server instances appear to the player as one game server. It is even possible to change the game server with a simple menu click.

So, in theory, how many players and games this server can handle, depends only on how much hardware you have.

Message Server

This one is for inter server communication, for example to deliver messages from a player to another player on a different game server.

Load Balancer (ablb)

An optional load balancer/proxy to make it possible to have several Login Server. It'll lookup running Login Servers and bridge client connections to one of them.

Admin Server

A Web interface to view and edit some data. For example Admins can view running services, games, account, can create account and IP bans, account keys etc.

On Linux this server must be run as root, because it binds the ports 80 and 443, which are privileged ports on Linux.

Client

Uses a single TCP stream for the game protocol.

Run Server

1. Run the data server abdada
2. Run the message server abmsgs
3. Run the file server abfile
4. Run the login server ablogin
5. Run the game server abserv

Optional run absadmin.

All servers must run with the same timezone, preferably UTC.

Run as NT service

Define WIN_SERVICE and recompile the server. It will create a Windows Service application. Use the *_svc.lua configuration files instead to log to a file instead of StdOut.

Install the services with the -install command line switch. Use -remove to uninstall it.

Structure of Bin/data directory

  data
   - maps
     - (Map)
       - index.xml  (defines the files)[0]
       - NavMesh.bin (Recast navigation mesh)
       - Scene.xml (Urho3D's scene file)
       - HeightField.hm (Heightfield file, .hm file generated with import or PNG)
   - models
   - scripts
     - actors
       - aoe (area of effect)
       - logic (portals etc)
       - npcs
       - ...
     - behaviors (behavior trees)
     - effects
       - conditions
       - ...
     - games
     - items (armor, weapons etc.)
     - includes (shared includes)
     - skills
     - quests
     - skills
     main.lua

[0] Map index.xml file format

<?xml version="1.0"?>
<index>
  <file type="Scene" src="Athena.xml" />
  <file type="NavMesh" src="all_tiles_navmesh.bin" />
  <file type="Terrain" src="athena.hm" />
</index>

Run Client

1. Start fw.exe
2. Create an account
3. Create a character
4. Enter world

Encoding

Everything is UTF-8 encoded. The Client sends only UTF-8 encoded strings to the server. All files on the server are UTF-8 encoded. So there is no additional conversion required.