# Bevy Project Patterns

## Start small

For workshop speed, stay in one crate.
When code grows, split by feature modules, not by technical layer only.

Good early structure:

```text
src/
├── main.rs
├── player.rs
├── ui.rs
├── state.rs
└── game.rs
```

Later:

```text
src/
├── main.rs
├── game/
│   ├── mod.rs
│   ├── plugin.rs
│   ├── events.rs
│   └── state.rs
├── player/
│   ├── mod.rs
│   ├── components.rs
│   ├── systems.rs
│   └── plugin.rs
└── ui/
    ├── mod.rs
    ├── components.rs
    ├── systems.rs
    └── plugin.rs
```

## Thin main

`main.rs` should mostly:

- create `App`
- add plugins
- init resources
- add states
- run

Business logic lives in feature plugins.

## Plugin boundaries

Each plugin should own:

- components
- resources
- events
- systems
- setup hooks

## Event flow example

Input system -> movement system -> collision system -> score event -> UI system

Good because:
- no direct UI coupling in gameplay code
- each step easy to test and inspect

## State flow example

`Loading -> Menu -> Playing -> GameOver`

Each state should have:
- enter setup
- update systems
- exit cleanup if needed

## Asset handling

- keep asset paths stable
- store handles in resources or components
- preload if startup hitches matter
- keep workshop assets tiny and few

## Debug helpers

Worth adding early:

- `Name` components on important entities
- debug print on critical events
- optional debug plugin
- one place for feature flags and tuning constants