
# Objective Fix https://github.com/bevyengine/bevy/issues/4530 - Make it easier to open/close/modify windows by setting them up as `Entity`s with a `Window` component. - Make multiple windows very simple to set up. (just add a `Window` component to an entity and it should open) ## Solution - Move all properties of window descriptor to ~components~ a component. - Replace `WindowId` with `Entity`. - ~Use change detection for components to update backend rather than events/commands. (The `CursorMoved`/`WindowResized`/... events are kept for user convenience.~ Check each field individually to see what we need to update, events are still kept for user convenience. --- ## Changelog - `WindowDescriptor` renamed to `Window`. - Width/height consolidated into a `WindowResolution` component. - Requesting maximization/minimization is done on the [`Window::state`] field. - `WindowId` is now `Entity`. ## Migration Guide - Replace `WindowDescriptor` with `Window`. - Change `width` and `height` fields in a `WindowResolution`, either by doing ```rust WindowResolution::new(width, height) // Explicitly // or using From<_> for tuples for convenience (1920., 1080.).into() ``` - Replace any `WindowCommand` code to just modify the `Window`'s fields directly and creating/closing windows is now by spawning/despawning an entity with a `Window` component like so: ```rust let window = commands.spawn(Window { ... }).id(); // open window commands.entity(window).despawn(); // close window ``` ## Unresolved - ~How do we tell when a window is minimized by a user?~ ~Currently using the `Resize(0, 0)` as an indicator of minimization.~ No longer attempting to tell given how finnicky this was across platforms, now the user can only request that a window be maximized/minimized. ## Future work - Move `exit_on_close` functionality out from windowing and into app(?) - https://github.com/bevyengine/bevy/issues/5621 - https://github.com/bevyengine/bevy/issues/7099 - https://github.com/bevyengine/bevy/issues/7098 Co-authored-by: Carter Anderson <mcanders1@gmail.com>
71 lines
2.4 KiB
Rust
71 lines
2.4 KiB
Rust
//! Illustrates parallel queries with `ParallelIterator`.
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use bevy::prelude::*;
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use rand::random;
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#[derive(Component, Deref)]
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struct Velocity(Vec2);
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fn spawn_system(mut commands: Commands, asset_server: Res<AssetServer>) {
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commands.spawn(Camera2dBundle::default());
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let texture = asset_server.load("branding/icon.png");
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for _ in 0..128 {
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commands.spawn((
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SpriteBundle {
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texture: texture.clone(),
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transform: Transform::from_scale(Vec3::splat(0.1)),
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..default()
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},
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Velocity(20.0 * Vec2::new(random::<f32>() - 0.5, random::<f32>() - 0.5)),
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));
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}
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}
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// Move sprites according to their velocity
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fn move_system(mut sprites: Query<(&mut Transform, &Velocity)>) {
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// Compute the new location of each sprite in parallel on the
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// ComputeTaskPool using batches of 32 sprites
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//
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// This example is only for demonstrative purposes. Using a
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// ParallelIterator for an inexpensive operation like addition on only 128
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// elements will not typically be faster than just using a normal Iterator.
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// See the ParallelIterator documentation for more information on when
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// to use or not use ParallelIterator over a normal Iterator.
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sprites.par_for_each_mut(32, |(mut transform, velocity)| {
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transform.translation += velocity.extend(0.0);
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});
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}
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// Bounce sprites outside the window
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fn bounce_system(windows: Query<&Window>, mut sprites: Query<(&Transform, &mut Velocity)>) {
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let window = windows.single();
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let width = window.width();
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let height = window.height();
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let left = width / -2.0;
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let right = width / 2.0;
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let bottom = height / -2.0;
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let top = height / 2.0;
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sprites
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// Batch size of 32 is chosen to limit the overhead of
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// ParallelIterator, since negating a vector is very inexpensive.
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.par_for_each_mut(32, |(transform, mut v)| {
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if !(left < transform.translation.x
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&& transform.translation.x < right
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&& bottom < transform.translation.y
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&& transform.translation.y < top)
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{
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// For simplicity, just reverse the velocity; don't use realistic bounces
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v.0 = -v.0;
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}
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});
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}
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_startup_system(spawn_system)
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.add_system(move_system)
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.add_system(bounce_system)
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.run();
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}
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