bevy/examples/asset/custom_asset_io.rs
Carter Anderson 81b53d15d4 Make Commands and World apis consistent (#1703)
Resolves #1253 #1562

This makes the Commands apis consistent with World apis. This moves to a "type state" pattern (like World) where the "current entity" is stored in an `EntityCommands` builder.

In general this tends to cuts down on indentation and line count. It comes at the cost of needing to type `commands` more and adding more semicolons to terminate expressions.

I also added `spawn_bundle` to Commands because this is a common enough operation that I think its worth providing a shorthand.
2021-03-23 00:23:40 +00:00

103 lines
3.3 KiB
Rust

use bevy::{
asset::{AssetIo, AssetIoError},
prelude::*,
utils::BoxedFuture,
};
use std::path::{Path, PathBuf};
/// A custom asset io implementation that simply defers to the platform default
/// implementation.
///
/// This can be used as a starting point for developing a useful implementation
/// that can defer to the default when needed.
struct CustomAssetIo(Box<dyn AssetIo>);
impl AssetIo for CustomAssetIo {
fn load_path<'a>(&'a self, path: &'a Path) -> BoxedFuture<'a, Result<Vec<u8>, AssetIoError>> {
println!("load_path({:?})", path);
self.0.load_path(path)
}
fn read_directory(
&self,
path: &Path,
) -> Result<Box<dyn Iterator<Item = PathBuf>>, AssetIoError> {
println!("read_directory({:?})", path);
self.0.read_directory(path)
}
fn is_directory(&self, path: &Path) -> bool {
println!("is_directory({:?})", path);
self.0.is_directory(path)
}
fn watch_path_for_changes(&self, path: &Path) -> Result<(), AssetIoError> {
println!("watch_path_for_changes({:?})", path);
self.0.watch_path_for_changes(path)
}
fn watch_for_changes(&self) -> Result<(), AssetIoError> {
println!("watch_for_changes()");
self.0.watch_for_changes()
}
}
/// A plugin used to execute the override of the asset io
struct CustomAssetIoPlugin;
impl Plugin for CustomAssetIoPlugin {
fn build(&self, app: &mut AppBuilder) {
// must get a hold of the task pool in order to create the asset server
let task_pool = app
.world()
.get_resource::<bevy::tasks::IoTaskPool>()
.expect("`IoTaskPool` resource not found.")
.0
.clone();
let asset_io = {
// the platform default asset io requires a reference to the app
// builder to find its configuration
let default_io = bevy::asset::create_platform_default_asset_io(app);
// create the custom asset io instance
CustomAssetIo(default_io)
};
// the asset server is constructed and added the resource manager
app.insert_resource(AssetServer::new(asset_io, task_pool));
}
}
fn main() {
App::build()
.add_plugins_with(DefaultPlugins, |group| {
// the custom asset io plugin must be inserted in-between the
// `CorePlugin' and `AssetPlugin`. It needs to be after the
// CorePlugin, so that the IO task pool has already been constructed.
// And it must be before the `AssetPlugin` so that the asset plugin
// doesn't create another instance of an assert server. In general,
// the AssetPlugin should still run so that other aspects of the
// asset system are initialized correctly.
group.add_before::<bevy::asset::AssetPlugin, _>(CustomAssetIoPlugin)
})
.add_startup_system(setup.system())
.run();
}
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut materials: ResMut<Assets<ColorMaterial>>,
) {
let texture_handle = asset_server.load("branding/icon.png");
commands.spawn_bundle(OrthographicCameraBundle::new_2d());
commands.spawn_bundle(SpriteBundle {
material: materials.add(texture_handle.into()),
..Default::default()
});
}