Zeus
This documentation describes features that are not fully implemented yet.
Zeus is the build and project management tool used for Athena game projects. The goal of Zeus is to simplify project creation, building, and deployment for users. Additionally, Zeus provides an API for working with Athena game projects for tools.
This documentation is about the technical details of Zeus and intended for developers
who want to contribute to it. If you are looking for the command-line interface's
help, run zeuscli help.
Frontends
Zeus has 2 frontends included in the GitHub repository.
- zeuscli, a command-line tool for automating and integrating with a command-line based development workflow.
- zeusgui, a graphical interface for ease of use. This frontend is currently implemented using the conrod UI library. It will be migrated to Phosphorus once that project is ready to be used.
Project Structure
A Zeus project contains everything needed for Zeus to know how to build it into a game, as well as cached data, plugins and Athena tools source code. Tool source is needed to allow plugins to be baked in at compile time. Zeus builds the tools behind the scenes to make it appear seamless.
The directory structure of a Zeus project is as following:
MyProject
├─ target # Anything in target is generated by Zeus, not meant to be included in the project's repository
│ ├─ debug/release # Contains binaries and processed assets for the game, plugins and tools
│ │ └─ <...>
│ └─ tools # Contains downloaded source files of tools
│ └─ <...>
├─ plugins # Contains source files for plugins specific to this project
│ ├─ <plugin name> # A cargo project folder for this plugin crate
│ │ ├─ ZeusPlugin.toml # Defines the plugin's metadata and entry point to Zeus
│ │ └─ <other normal cargo files>
│ └─ <...>
├─ .gitignore
└─ Zeus.toml # Defines the project's metadata, build parameters, and dependencies to Zeus
Zeus.toml
The Zeus.toml file defines metadata, build parameters and dependencies to be used for the project it's in. A Zeus project can have only one Zeus.toml. The following is an example Zeus.toml file.
[game]
name = "My Game"
version = "0.0.1"
authors = ["Jane Doe"]
[dependencies-tools]
# Version strings and how they're resolved to specific versions match cargo
launcher = "1.0.*"
editor = "1.0.5"
External plugin dependencies are planned but currently there is no good design for them yet. Tool dependencies are brought in through git by looking up the highest version that matches the given version string. If the tool is not in the list in the toml file, Zeus will only bring in the tool if it's considered required. The only required tools are "launcher" and "editor".
Asset Processing
Zeus should process assets to prepare them for use at runtime. No designs are made for this yet.
Internals
The core Zeus library is relatively simple. It contains a central Project struct
which represents an Athena project. This struct is contained in the module project.
Communication to git is done using the command line tool. This is to avoid a C dependency.
zeuscli
Individual commands are implemented as functions that have their own Docopt args.
A command function can return a Box<Error> to signal that the command has failed.
The error will then be displayed using the Display trait.
zeusgui
Design of zeusgui is still up in the air and not well defined. A strict design will be created once Phosphorus is usable.
Diagrams
