1efc762924
# Objective
- Introduce a stable alternative to
[`std::any::type_name`](https://doc.rust-lang.org/std/any/fn.type_name.html).
- Rewrite of #5805 with heavy inspiration in design.
- On the path to #5830.
- Part of solving #3327.
## Solution
- Add a `TypePath` trait for static stable type path/name information.
- Add a `TypePath` derive macro.
- Add a `impl_type_path` macro for implementing internal and foreign
types in `bevy_reflect`.
---
## Changelog
- Added `TypePath` trait.
- Added `DynamicTypePath` trait and `get_type_path` method to `Reflect`.
- Added a `TypePath` derive macro.
- Added a `bevy_reflect::impl_type_path` for implementing `TypePath` on
internal and foreign types in `bevy_reflect`.
- Changed `bevy_reflect::utility::(Non)GenericTypeInfoCell` to
`(Non)GenericTypedCell<T>` which allows us to be generic over both
`TypeInfo` and `TypePath`.
- `TypePath` is now a supertrait of `Asset`, `Material` and
`Material2d`.
- `impl_reflect_struct` needs a `#[type_path = "..."]` attribute to be
specified.
- `impl_reflect_value` needs to either specify path starting with a
double colon (`::core::option::Option`) or an `in my_crate::foo`
declaration.
- Added `bevy_reflect_derive::ReflectTypePath`.
- Most uses of `Ident` in `bevy_reflect_derive` changed to use
`ReflectTypePath`.
## Migration Guide
- Implementors of `Asset`, `Material` and `Material2d` now also need to
derive `TypePath`.
- Manual implementors of `Reflect` will need to implement the new
`get_type_path` method.
## Open Questions
- [x] ~This PR currently does not migrate any usages of
`std::any::type_name` to use `bevy_reflect::TypePath` to ease the review
process. Should it?~ Migration will be left to a follow-up PR.
- [ ] This PR adds a lot of `#[derive(TypePath)]` and `T: TypePath` to
satisfy new bounds, mostly when deriving `TypeUuid`. Should we make
`TypePath` a supertrait of `TypeUuid`? [Should we remove `TypeUuid` in
favour of
`TypePath`?](2afbd85532 (r961067892))
68 lines
1.7 KiB
Rust
68 lines
1.7 KiB
Rust
//! Implements loader for a custom asset type.
|
|
|
|
use bevy::{
|
|
asset::{AssetLoader, LoadContext, LoadedAsset},
|
|
prelude::*,
|
|
reflect::{TypePath, TypeUuid},
|
|
utils::BoxedFuture,
|
|
};
|
|
use serde::Deserialize;
|
|
|
|
#[derive(Debug, Deserialize, TypeUuid, TypePath)]
|
|
#[uuid = "39cadc56-aa9c-4543-8640-a018b74b5052"]
|
|
pub struct CustomAsset {
|
|
pub value: i32,
|
|
}
|
|
|
|
#[derive(Default)]
|
|
pub struct CustomAssetLoader;
|
|
|
|
impl AssetLoader for CustomAssetLoader {
|
|
fn load<'a>(
|
|
&'a self,
|
|
bytes: &'a [u8],
|
|
load_context: &'a mut LoadContext,
|
|
) -> BoxedFuture<'a, Result<(), bevy::asset::Error>> {
|
|
Box::pin(async move {
|
|
let custom_asset = ron::de::from_bytes::<CustomAsset>(bytes)?;
|
|
load_context.set_default_asset(LoadedAsset::new(custom_asset));
|
|
Ok(())
|
|
})
|
|
}
|
|
|
|
fn extensions(&self) -> &[&str] {
|
|
&["custom"]
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
.init_resource::<State>()
|
|
.add_asset::<CustomAsset>()
|
|
.init_asset_loader::<CustomAssetLoader>()
|
|
.add_systems(Startup, setup)
|
|
.add_systems(Update, print_on_load)
|
|
.run();
|
|
}
|
|
|
|
#[derive(Resource, Default)]
|
|
struct State {
|
|
handle: Handle<CustomAsset>,
|
|
printed: bool,
|
|
}
|
|
|
|
fn setup(mut state: ResMut<State>, asset_server: Res<AssetServer>) {
|
|
state.handle = asset_server.load("data/asset.custom");
|
|
}
|
|
|
|
fn print_on_load(mut state: ResMut<State>, custom_assets: ResMut<Assets<CustomAsset>>) {
|
|
let custom_asset = custom_assets.get(&state.handle);
|
|
if state.printed || custom_asset.is_none() {
|
|
return;
|
|
}
|
|
|
|
info!("Custom asset loaded: {:?}", custom_asset.unwrap());
|
|
state.printed = true;
|
|
}
|