ffecb05a0a
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release. The examples are all ported over and operational with a few exceptions: * I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure. * Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example. * Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
61 lines
2.3 KiB
Rust
61 lines
2.3 KiB
Rust
// This example shows how you can know when a `Component` has been removed, so you can react to it.
|
|
|
|
use bevy::prelude::*;
|
|
|
|
fn main() {
|
|
// Information regarding removed `Component`s is discarded at the end of each frame, so you need
|
|
// to react to the removal before the frame is over.
|
|
//
|
|
// Also, `Components` are removed via a `Command`. `Command`s are applied after a stage has
|
|
// finished executing. So you need to react to the removal at some stage after the
|
|
// `Component` is removed.
|
|
//
|
|
// With these constraints in mind we make sure to place the system that removes a `Component` on
|
|
// the `CoreStage::Update' stage, and the system that reacts on the removal on the
|
|
// `CoreStage::PostUpdate` stage.
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
.add_startup_system(setup)
|
|
.add_system_to_stage(CoreStage::Update, remove_component)
|
|
.add_system_to_stage(CoreStage::PostUpdate, react_on_removal)
|
|
.run();
|
|
}
|
|
|
|
// This `Struct` is just used for convenience in this example. This is the `Component` we'll be
|
|
// giving to the `Entity` so we have a `Component` to remove in `remove_component()`.
|
|
#[derive(Component)]
|
|
struct MyComponent;
|
|
|
|
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
|
|
commands.spawn_bundle(OrthographicCameraBundle::new_2d());
|
|
commands
|
|
.spawn_bundle(SpriteBundle {
|
|
texture: asset_server.load("branding/icon.png"),
|
|
..Default::default()
|
|
})
|
|
.insert(MyComponent); // Add the `Component`.
|
|
}
|
|
|
|
fn remove_component(
|
|
time: Res<Time>,
|
|
mut commands: Commands,
|
|
query: Query<Entity, With<MyComponent>>,
|
|
) {
|
|
// After two seconds have passed the `Component` is removed.
|
|
if time.seconds_since_startup() > 2.0 {
|
|
if let Some(entity) = query.iter().next() {
|
|
commands.entity(entity).remove::<MyComponent>();
|
|
}
|
|
}
|
|
}
|
|
|
|
fn react_on_removal(removed: RemovedComponents<MyComponent>, mut query: Query<&mut Sprite>) {
|
|
// `RemovedComponents<T>::iter()` returns an interator with the `Entity`s that had their
|
|
// `Component` `T` (in this case `MyComponent`) removed at some point earlier during the frame.
|
|
for entity in removed.iter() {
|
|
if let Ok(mut sprite) = query.get_mut(entity) {
|
|
sprite.color.set_r(0.0);
|
|
}
|
|
}
|
|
}
|