Dexterous Developer

An experimental hot reload system for the bevy game engine. Inspired by DGriffin91's Ridiculous bevy hot reloading - adding the ability to re-load arbitrary systems, and the ability to transform resource/component structures over time.

Fuller documentation is available at: https://lee-orr.github.io/dexterous_developer/

Features

• Define the reloadable areas of your game explicitly - which can include systems, components, states, events and resources (w/ some limitations)
• Reset resources to a default or pre-determined value upon reload
• Serialize/deserialize your reloadable resources & components, allowing you to evolve their schemas so long as they are compatible with the de-serializer (using rmp_serde)
• Mark entities to get removed on hot reload
• Run systems after hot-reload
• Create functions to set up & tear down upon either entering/exiting a state or on hot reload
• Only includes any hot reload capacity in your build when you explicitly enable it - such as by using the CLI launcher
• Cross-platform/cross-device hot reload - run a "hot reload server" on a development environment, and execute the application elsewhere. For best results, the dev environment should be a linux device or a Linux-based development container, but it can be configured to work directly on windows or mac as well - albeit less reliably. Support for cross-compilation directly on windows/mac is not a priority, since those can always be set up to host a docker-in-docker environment with linux, which is confirmed to work. This feature does not work in the current version, but will be re-implemented in the future

Known issues

• Won't work on mobile or WASM

Installation

Grab the CLI by running: cargo install dexterous_developer_cli.

You'll be able to run the dexterous version of your code by running dexterous_developer_cli run in your terminal.

In your Cargo.toml add the following:

[lib]
name = "lib_THE_NAME_OF_YOUR_GAME"
path = "src/lib.rs"
crate-type = ["rlib"]

[dependencies]
bevy = "0.13"
dexterous_developer = "0.1.1"
serde = "1" # If you want the serialization capacities

[package.metadata]
hot_reload_features = ["bevy/dynamic_linking", "bevy/embedded_watcher"] # this injects these features into the build, enabling the use of bevy's dynamic linking and asset hot reload capacity.

If your game is not a library yet, move all your main logic to lib.rs rather than main.rs. Then, in your main.rs - call the bevy_main function:

fn main() {
    lib_NAME_OF_YOUR_GAME::bevy_main();
}

and in your lib.rs, your main function should become:

#[hot_bevy_main]
pub fn bevy_main(initial_plugins: impl InitialPlugins) {
    App::new()
        .add_plugins(initial_plugins.initialize::<DefaultPlugins>()) // You can use either DefaultPlugins or MinimnalPlugins here, and use "set" on this as you would with them
    // Here you can do what you'd normally do with app
    // ... and so on
}

If you have a plugin where you want to add reloadable elements, add the following in the file defining the plugin:

impl Plugin for MyPlugin {
    fn build(&self, app: &mut App) {
        app
            .setup_reloadable_elements::<reloadable>();
    }
}

#[dexterous_developer_setup]
fn reloadable(app: &mut ReloadableAppContents) {
    app
        .add_systems(Update, this_system_will_reload);
}

Bevy Version Support