bevy/crates/bevy_asset/src/direct_access_ext.rs
Nicola Papale f7f7e326e5
Add methods to directly load assets from World (#12023)
# Objective

`FromWorld` is often used to group loading and creation of assets for
resources.

With this setup, users often end up repetitively calling
`.resource::<AssetServer>` and `.resource_mut::<Assets<T>>`, and may
have difficulties handling lifetimes of the returned references.

## Solution

Add extension methods to `World` to add and load assets, through a new
extension trait defined in `bevy_asset`.

### Other considerations

* This might be a bit too "magic", as it makes implicit the resource
access.
* We could also implement `DirectAssetAccessExt` on `App`, but it didn't
feel necessary, as `FromWorld` is the principal use-case here.

---

## Changelog

* Add the `DirectAssetAccessExt` trait, which adds the `add_asset`,
`load_asset` and `load_asset_with_settings` method to the `World` type.
2024-02-27 00:28:26 +00:00

50 lines
1.8 KiB
Rust

//! Add methods on `World` to simplify loading assets when all
//! you have is a `World`.
use bevy_ecs::world::World;
use crate::{meta::Settings, Asset, AssetPath, AssetServer, Assets, Handle};
pub trait DirectAssetAccessExt {
/// Insert an asset similarly to [`Assets::add`].
fn add_asset<A: Asset>(&mut self, asset: impl Into<A>) -> Handle<A>;
/// Load an asset similarly to [`AssetServer::load`].
fn load_asset<'a, A: Asset>(&self, path: impl Into<AssetPath<'a>>) -> Handle<A>;
/// Load an asset with settings, similarly to [`AssetServer::load_with_settings`].
fn load_asset_with_settings<'a, A: Asset, S: Settings>(
&self,
path: impl Into<AssetPath<'a>>,
settings: impl Fn(&mut S) + Send + Sync + 'static,
) -> Handle<A>;
}
impl DirectAssetAccessExt for World {
/// Insert an asset similarly to [`Assets::add`].
///
/// # Panics
/// If `self` doesn't have an [`AssetServer`] resource initialized yet.
fn add_asset<'a, A: Asset>(&mut self, asset: impl Into<A>) -> Handle<A> {
self.resource_mut::<Assets<A>>().add(asset)
}
/// Load an asset similarly to [`AssetServer::load`].
///
/// # Panics
/// If `self` doesn't have an [`AssetServer`] resource initialized yet.
fn load_asset<'a, A: Asset>(&self, path: impl Into<AssetPath<'a>>) -> Handle<A> {
self.resource::<AssetServer>().load(path)
}
/// Load an asset with settings, similarly to [`AssetServer::load_with_settings`].
///
/// # Panics
/// If `self` doesn't have an [`AssetServer`] resource initialized yet.
fn load_asset_with_settings<'a, A: Asset, S: Settings>(
&self,
path: impl Into<AssetPath<'a>>,
settings: impl Fn(&mut S) + Send + Sync + 'static,
) -> Handle<A> {
self.resource::<AssetServer>()
.load_with_settings(path, settings)
}
}