Commit Graph

19 Commits

Author SHA1 Message Date
urben1680
732b2e0c79
Track spawn Tick of entities, offer methods, query data SpawnDetails and query filter Spawned (#19047)
# Objective

In my own project I was encountering the issue to find out which
entities were spawned after applying commands. I began maintaining a
vector of all entities with generational information before and after
applying the command and diffing it. This was awfully complicated though
and has no constant complexity but grows with the number of entities.

## Solution

Looking at `EntyMeta` it seemed obvious to me that struct can track the
tick just as it does with `MaybeLocation`, updated from the same call.
After that it became almost a given to also introduce query data
`SpawnDetails` which offers methods to get the spawn tick and location,
and query filter `Spawned` that filters entities out that were not
spawned since the last run.

## Testing

I expanded a few tests and added new ones, though maybe I forgot a group
of tests that should be extended too. I basically searched `bevy_ecs`
for mentions of `Changed` and `Added` to see where the tests and docs
are.

Benchmarks of spawn/despawn can be found
[here](https://github.com/bevyengine/bevy/pull/19047#issuecomment-2852181374).

---

## Showcase

From the added docs, systems with equal complexity since the filter is
not archetypal:
```rs
fn system1(q: Query<Entity, Spawned>) {
    for entity in &q { /* entity spawned */ }
}

fn system2(query: Query<(Entity, SpawnDetails)>) {
    for (entity, spawned) in &query {
        if spawned.is_spawned() { /* entity spawned */ }
    }
}
```

`SpawnedDetails` has a few more methods:

```rs
fn print_spawn_details(query: Query<(Entity, SpawnDetails)>) {
    for (entity, spawn_details) in &query {
        if spawn_details.is_spawned() {
            print!("new ");
        }
        println!(
            "entity {:?} spawned at {:?} by {:?}",
            entity,
            spawn_details.spawned_at(),
            spawn_details.spawned_by()
        );        
    }
}
```

## Changes

No public api was changed, I only added to it. That is why I added no
migration guide.

- query data `SpawnDetails`
- query filter `Spawned`
- method `Entities::entity_get_spawned_or_despawned_at`
- method `EntityRef::spawned_at`
- method `EntityMut::spawned_at`
- method `EntityWorldMut::spawned_at`
- method `UnsafeEntityCell::spawned_at`
- method `FilteredEntityRef::spawned_at`
- method `FilteredEntityMut::spawned_at`
- method `EntityRefExcept::spawned_at`
- method `EntityMutExcept::spawned_at`

---------

Co-authored-by: Eagster <79881080+ElliottjPierce@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-05-08 14:57:33 +00:00
Eagster
12aba64900
Make entity generation a new type and remove identifier (#19121)
# Objective

This is a followup to #18704 . There's lots more followup work, but this
is the minimum to unblock #18670, etc.

This direction has been given the green light by Alice
[here](https://github.com/bevyengine/bevy/pull/18704#issuecomment-2853368129).

## Solution

I could have split this over multiple PRs, but I figured skipping
straight here would be easiest for everyone and would unblock things the
quickest.

This removes the now no longer needed `identifier` module and makes
`Entity::generation` go from `NonZeroU32` to `struct
EntityGeneration(u32)`.

## Testing

CI

---------

Co-authored-by: Mark Nokalt <marknokalt@live.com>
2025-05-08 04:03:05 +00:00
Eagster
0b4858726c
Make entity::index non max (#18704)
# Objective

There are two problems this aims to solve. 

First, `Entity::index` is currently a `u32`. That means there are
`u32::MAX + 1` possible entities. Not only is that awkward, but it also
make `Entity` allocation more difficult. I discovered this while working
on remote entity reservation, but even on main, `Entities` doesn't
handle the `u32::MAX + 1` entity very well. It can not be batch reserved
because that iterator uses exclusive ranges, which has a maximum upper
bound of `u32::MAX - 1`. In other words, having `u32::MAX` as a valid
index can be thought of as a bug right now. We either need to make that
invalid (this PR), which makes Entity allocation cleaner and makes
remote reservation easier (because the length only needs to be u32
instead of u64, which, in atomics is a big deal), or we need to take
another pass at `Entities` to make it handle the `u32::MAX` index
properly.

Second, `TableRow`, `ArchetypeRow` and `EntityIndex` (a type alias for
u32) all have `u32` as the underlying type. That means using these as
the index type in a `SparseSet` uses 64 bits for the sparse list because
it stores `Option<IndexType>`. By using `NonMaxU32` here, we cut the
memory of that list in half. To my knowledge, `EntityIndex` is the only
thing that would really benefit from this niche. `TableRow` and
`ArchetypeRow` I think are not stored in an `Option` in bulk. But if
they ever are, this would help. Additionally this ensures
`TableRow::INVALID` and `ArchetypeRow::INVALID` never conflict with an
actual row, which in a nice bonus.

As a related note, if we do components as entities where `ComponentId`
becomes `Entity`, the the `SparseSet<ComponentId>` will see a similar
memory improvement too.

## Solution

Create a new type `EntityRow` that wraps `NonMaxU32`, similar to
`TableRow` and `ArchetypeRow`.
Change `Entity::index` to this type.

## Downsides

`NonMax` is implemented as a `NonZero` with a binary inversion. That
means accessing and storing the value takes one more instruction. I
don't think that's a big deal, but it's worth mentioning.

As a consequence, `to_bits` uses `transmute` to skip the inversion which
keeps it a nop. But that also means that ordering has now flipped. In
other words, higher indices are considered less than lower indices. I
don't think that's a problem, but it's also worth mentioning.

## Alternatives

We could keep the index as a u32 type and just document that `u32::MAX`
is invalid, modifying `Entities` to ensure it never gets handed out.
(But that's not enforced by the type system.) We could still take
advantage of the niche here in `ComponentSparseSet`. We'd just need some
unsafe manual conversions, which is probably fine, but opens up the
possibility for correctness problems later.

We could change `Entities` to fully support the `u32::MAX` index. (But
that makes `Entities` more complex and potentially slightly slower.)

## Testing

- CI
- A few tests were changed because they depend on different ordering and
`to_bits` values.

## Future Work

- It might be worth removing the niche on `Entity::generation` since
there is now a different niche.
- We could move `Entity::generation` into it's own type too for clarity.
- We should change `ComponentSparseSet` to take advantage of the new
niche. (This PR doesn't change that yet.)
- Consider removing or updating `Identifier`. This is only used for
`Entity`, so it might be worth combining since `Entity` is now more
unique.

---------

Co-authored-by: atlv <email@atlasdostal.com>
Co-authored-by: Zachary Harrold <zac@harrold.com.au>
2025-05-07 18:20:30 +00:00
Chris Russell
9e2bd8ac18
Generic SystemParam impls for Option and Result (#18766)
# Objective

Provide a generic `impl SystemParam for Option<P>` that uses system
parameter validation. This immediately gives useful impls for params
like `EventReader` and `GizmosState` that are defined in terms of `Res`.
It also allows third-party system parameters to be usable with `Option`,
which was previously impossible due to orphan rules.

Note that this is a behavior change for `Option<Single>`. It currently
fails validation if there are multiple matching entities, but with this
change it will pass validation and produce `None`.

Also provide an impl for `Result<P, SystemParamValidationError>`. This
allows systems to inspect the error if necessary, either for bubbling it
up or for checking the `skipped` flag.

Fixes #12634
Fixes #14949
Related to #18516

## Solution

Add generic `SystemParam` impls for `Option` and `Result`, and remove
the impls for specific types.

Update documentation and `fallible_params` example with the new
semantics for `Option<Single>`.
2025-05-07 18:20:08 +00:00
Joona Aalto
7b1c9f192e
Adopt consistent FooSystems naming convention for system sets (#18900)
# Objective

Fixes a part of #14274.

Bevy has an incredibly inconsistent naming convention for its system
sets, both internally and across the ecosystem.

<img alt="System sets in Bevy"
src="https://github.com/user-attachments/assets/d16e2027-793f-4ba4-9cc9-e780b14a5a1b"
width="450" />

*Names of public system set types in Bevy*

Most Bevy types use a naming of `FooSystem` or just `Foo`, but there are
also a few `FooSystems` and `FooSet` types. In ecosystem crates on the
other hand, `FooSet` is perhaps the most commonly used name in general.
Conventions being so wildly inconsistent can make it harder for users to
pick names for their own types, to search for system sets on docs.rs, or
to even discern which types *are* system sets.

To reign in the inconsistency a bit and help unify the ecosystem, it
would be good to establish a common recommended naming convention for
system sets in Bevy itself, similar to how plugins are commonly suffixed
with `Plugin` (ex: `TimePlugin`). By adopting a consistent naming
convention in first-party Bevy, we can softly nudge ecosystem crates to
follow suit (for types where it makes sense to do so).

Choosing a naming convention is also relevant now, as the [`bevy_cli`
recently adopted
lints](https://github.com/TheBevyFlock/bevy_cli/pull/345) to enforce
naming for plugins and system sets, and the recommended naming used for
system sets is still a bit open.

## Which Name To Use?

Now the contentious part: what naming convention should we actually
adopt?

This was discussed on the Bevy Discord at the end of last year, starting
[here](<https://discord.com/channels/691052431525675048/692572690833473578/1310659954683936789>).
`FooSet` and `FooSystems` were the clear favorites, with `FooSet` very
narrowly winning an unofficial poll. However, it seems to me like the
consensus was broadly moving towards `FooSystems` at the end and after
the poll, with Cart
([source](https://discord.com/channels/691052431525675048/692572690833473578/1311140204974706708))
and later Alice
([source](https://discord.com/channels/691052431525675048/692572690833473578/1311092530732859533))
and also me being in favor of it.

Let's do a quick pros and cons list! Of course these are just what I
thought of, so take it with a grain of salt.

`FooSet`:

- Pro: Nice and short!
- Pro: Used by many ecosystem crates.
- Pro: The `Set` suffix comes directly from the trait name `SystemSet`.
- Pro: Pairs nicely with existing APIs like `in_set` and
`configure_sets`.
- Con: `Set` by itself doesn't actually indicate that it's related to
systems *at all*, apart from the implemented trait. A set of what?
- Con: Is `FooSet` a set of `Foo`s or a system set related to `Foo`? Ex:
`ContactSet`, `MeshSet`, `EnemySet`...

`FooSystems`:

- Pro: Very clearly indicates that the type represents a collection of
systems. The actual core concept, system(s), is in the name.
- Pro: Parallels nicely with `FooPlugins` for plugin groups.
- Pro: Low risk of conflicts with other names or misunderstandings about
what the type is.
- Pro: In most cases, reads *very* nicely and clearly. Ex:
`PhysicsSystems` and `AnimationSystems` as opposed to `PhysicsSet` and
`AnimationSet`.
- Pro: Easy to search for on docs.rs.
- Con: Usually results in longer names.
- Con: Not yet as widely used.

Really the big problem with `FooSet` is that it doesn't actually
describe what it is. It describes what *kind of thing* it is (a set of
something), but not *what it is a set of*, unless you know the type or
check its docs or implemented traits. `FooSystems` on the other hand is
much more self-descriptive in this regard, at the cost of being a bit
longer to type.

Ultimately, in some ways it comes down to preference and how you think
of system sets. Personally, I was originally in favor of `FooSet`, but
have been increasingly on the side of `FooSystems`, especially after
seeing what the new names would actually look like in Avian and now
Bevy. I prefer it because it usually reads better, is much more clearly
related to groups of systems than `FooSet`, and overall *feels* more
correct and natural to me in the long term.

For these reasons, and because Alice and Cart also seemed to share a
preference for it when it was previously being discussed, I propose that
we adopt a `FooSystems` naming convention where applicable.

## Solution

Rename Bevy's system set types to use a consistent `FooSet` naming where
applicable.

- `AccessibilitySystem` → `AccessibilitySystems`
- `GizmoRenderSystem` → `GizmoRenderSystems`
- `PickSet` → `PickingSystems`
- `RunFixedMainLoopSystem` → `RunFixedMainLoopSystems`
- `TransformSystem` → `TransformSystems`
- `RemoteSet` → `RemoteSystems`
- `RenderSet` → `RenderSystems`
- `SpriteSystem` → `SpriteSystems`
- `StateTransitionSteps` → `StateTransitionSystems`
- `RenderUiSystem` → `RenderUiSystems`
- `UiSystem` → `UiSystems`
- `Animation` → `AnimationSystems`
- `AssetEvents` → `AssetEventSystems`
- `TrackAssets` → `AssetTrackingSystems`
- `UpdateGizmoMeshes` → `GizmoMeshSystems`
- `InputSystem` → `InputSystems`
- `InputFocusSet` → `InputFocusSystems`
- `ExtractMaterialsSet` → `MaterialExtractionSystems`
- `ExtractMeshesSet` → `MeshExtractionSystems`
- `RumbleSystem` → `RumbleSystems`
- `CameraUpdateSystem` → `CameraUpdateSystems`
- `ExtractAssetsSet` → `AssetExtractionSystems`
- `Update2dText` → `Text2dUpdateSystems`
- `TimeSystem` → `TimeSystems`
- `AudioPlaySet` → `AudioPlaybackSystems`
- `SendEvents` → `EventSenderSystems`
- `EventUpdates` → `EventUpdateSystems`

A lot of the names got slightly longer, but they are also a lot more
consistent, and in my opinion the majority of them read much better. For
a few of the names I took the liberty of rewording things a bit;
definitely open to any further naming improvements.

There are still also cases where the `FooSystems` naming doesn't really
make sense, and those I left alone. This primarily includes system sets
like `Interned<dyn SystemSet>`, `EnterSchedules<S>`, `ExitSchedules<S>`,
or `TransitionSchedules<S>`, where the type has some special purpose and
semantics.

## Todo

- [x] Should I keep all the old names as deprecated type aliases? I can
do this, but to avoid wasting work I'd prefer to first reach consensus
on whether these renames are even desired.
- [x] Migration guide
- [x] Release notes
2025-05-06 15:18:03 +00:00
mgi388
7a1fcb7fe7
Rename StateScoped to DespawnOnExitState and add DespawnOnEnterState (#18818)
# Objective

- Alternative to and builds on top of #16284.
- Fixes #15849.

## Solution

- Rename component `StateScoped` to `DespawnOnExitState`.
- Rename system `clear_state_scoped_entities` to
`despawn_entities_on_exit_state`.
- Add `DespawnOnEnterState` and `despawn_entities_on_enter_state` which
is the `OnEnter` equivalent.

> [!NOTE]
> Compared to #16284, the main change is that I did the rename in such a
way as to keep the terms `OnExit` and `OnEnter` together. In my own
game, I was adding `VisibleOnEnterState` and `HiddenOnExitState` and
when naming those, I kept the `OnExit` and `OnEnter` together. When I
checked #16284 it stood out to me that the naming was a bit awkward.
Putting the `State` in the middle and breaking up `OnEnter` and `OnExit`
also breaks searching for those terms.

## Open questions

1. Should we split `enable_state_scoped_entities` into two functions,
one for the `OnEnter` and one for the `OnExit`? I personally have zero
need thus far for the `OnEnter` version, so I'd be interested in not
having this enabled unless I ask for it.
2. If yes to 1., should we follow my lead in my `Visibility` state
components (see below) and name these
`app.enable_despawn_entities_on_enter_state()` and
`app.enable_despawn_entities_on_exit_state()`, which IMO says what it
does on the tin?

## Testing

Ran all changed examples.

## Side note: `VisibleOnEnterState` and `HiddenOnExitState`

For reference to anyone else and to help with the open questions, I'm
including the code I wrote for controlling entity visibility when a
state is entered/exited.

<details>
<summary>visibility.rs</summary>

```rust
use bevy_app::prelude::*;
use bevy_ecs::prelude::*;
use bevy_reflect::prelude::*;
use bevy_render::prelude::*;
use bevy_state::{prelude::*, state::StateTransitionSteps};
use tracing::*;

pub trait AppExtStates {
    fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self;

    fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self;
}

impl AppExtStates for App {
    fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self {
        self.main_mut()
            .enable_visible_entities_on_enter_state::<S>();
        self
    }

    fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self {
        self.main_mut().enable_hidden_entities_on_exit_state::<S>();
        self
    }
}

impl AppExtStates for SubApp {
    fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self {
        if !self
            .world()
            .contains_resource::<Events<StateTransitionEvent<S>>>()
        {
            let name = core::any::type_name::<S>();
            warn!("Visible entities on enter state are enabled for state `{}`, but the state isn't installed in the app!", name);
        }
        // We work with [`StateTransition`] in set
        // [`StateTransitionSteps::ExitSchedules`] as opposed to [`OnExit`],
        // because [`OnExit`] only runs for one specific variant of the state.
        self.add_systems(
            StateTransition,
            update_to_visible_on_enter_state::<S>.in_set(StateTransitionSteps::ExitSchedules),
        )
    }

    fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self {
        if !self
            .world()
            .contains_resource::<Events<StateTransitionEvent<S>>>()
        {
            let name = core::any::type_name::<S>();
            warn!("Hidden entities on exit state are enabled for state `{}`, but the state isn't installed in the app!", name);
        }
        // We work with [`StateTransition`] in set
        // [`StateTransitionSteps::ExitSchedules`] as opposed to [`OnExit`],
        // because [`OnExit`] only runs for one specific variant of the state.
        self.add_systems(
            StateTransition,
            update_to_hidden_on_exit_state::<S>.in_set(StateTransitionSteps::ExitSchedules),
        )
    }
}

#[derive(Clone, Component, Debug, Reflect)]
#[reflect(Component, Debug)]
pub struct VisibleOnEnterState<S: States>(pub S);

#[derive(Clone, Component, Debug, Reflect)]
#[reflect(Component, Debug)]
pub struct HiddenOnExitState<S: States>(pub S);

/// Makes entities marked with [`VisibleOnEnterState<S>`] visible when the state
/// `S` is entered.
pub fn update_to_visible_on_enter_state<S: States>(
    mut transitions: EventReader<StateTransitionEvent<S>>,
    mut query: Query<(&VisibleOnEnterState<S>, &mut Visibility)>,
) {
    // We use the latest event, because state machine internals generate at most
    // 1 transition event (per type) each frame. No event means no change
    // happened and we skip iterating all entities.
    let Some(transition) = transitions.read().last() else {
        return;
    };
    if transition.entered == transition.exited {
        return;
    }
    let Some(entered) = &transition.entered else {
        return;
    };
    for (binding, mut visibility) in query.iter_mut() {
        if binding.0 == *entered {
            visibility.set_if_neq(Visibility::Visible);
        }
    }
}

/// Makes entities marked with [`HiddenOnExitState<S>`] invisible when the state
/// `S` is exited.
pub fn update_to_hidden_on_exit_state<S: States>(
    mut transitions: EventReader<StateTransitionEvent<S>>,
    mut query: Query<(&HiddenOnExitState<S>, &mut Visibility)>,
) {
    // We use the latest event, because state machine internals generate at most
    // 1 transition event (per type) each frame. No event means no change
    // happened and we skip iterating all entities.
    let Some(transition) = transitions.read().last() else {
        return;
    };
    if transition.entered == transition.exited {
        return;
    }
    let Some(exited) = &transition.exited else {
        return;
    };
    for (binding, mut visibility) in query.iter_mut() {
        if binding.0 == *exited {
            visibility.set_if_neq(Visibility::Hidden);
        }
    }
}
```

</details>

---------

Co-authored-by: Benjamin Brienen <Benjamin.Brienen@outlook.com>
Co-authored-by: Ben Frankel <ben.frankel7@gmail.com>
2025-05-06 00:37:04 +00:00
Eagster
af8d12c3e1
deprecate SimpleExecutor (#18753)
# Objective

Contributes to #18741 and #18453.

## Solution

Deprecate `SimpleExecutor`. If users run into migration issues, we can
backtrack. Otherwise, we follow this up with #18741

We can't easily deprecate the module too because of
[this](https://github.com/rust-lang/rust/issues/47238).

## Testing

CI

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Cyrill Schenkel <cyrill.schenkel@gmail.com>
2025-05-06 00:21:57 +00:00
re0312
5ed8e0639a
Merge ObserverState and Observer into single component (#18728)
# Objective

- bevy removed `Observe` type parameters in #15151 ,it enables merging
`Observer` and `ObserverState ` into a single component. with this
consolidation ,we can improve efficiency while reducing boilerplate.

## Solution

- remove `ObserverState `and merge it  into `Observer`

## Testing

40%~60% performance win due to removal of redundant look up.

![image](https://github.com/user-attachments/assets/eb1d46cb-cca3-4c2b-948c-bf4ecb617de9)

This also improves ergonomics when using dynamic observer
```rust
// previously 
world.spawn(ObserverState {
            // SAFETY: we registered `event_a` above and it matches the type of EventA
            descriptor: unsafe { ObserverDescriptor::default().with_events(vec![event_a]) },
            runner: |mut world, _trigger, _ptr, _propagate| {
                world.resource_mut::<Order>().observed("event_a");
            },
            ..Default::default()
        });

// now
let observe = unsafe {
    Observer::with_dynamic_runner(|mut world, _trigger, _ptr, _propagate| {
        world.resource_mut::<Order>().observed("event_a");
    })
    .with_event(event_a)
};
world.spawn(observe);
```
2025-05-06 00:12:27 +00:00
Eagster
bfc76c589e
Remove insert_or_spawn function family (#18148)
# Objective

Based on and closes #18054, this PR builds on #18035 and #18147 to
remove:

- `Commands::insert_or_spawn_batch`
- `Entities::alloc_at_without_replacement`
- `Entities::alloc_at`
- `entity::AllocAtWithoutReplacement`
- `World::insert_or_spawn_batch`
- `World::insert_or_spawn_batch_with_caller`

## Testing

Just removing unused, deprecated code, so no new tests. Note that as of
writing, #18035 is still under testing and review.

## Future Work

Per
[this](https://github.com/bevyengine/bevy/issues/18054#issuecomment-2689088899)
comment on #18054, there may be additional performance improvements
possible to the entity allocator now that `alloc_at` no longer is
supported. At a glance, I don't see anything obvious to improve, but it
may be worth further investigation in the future.

---------

Co-authored-by: JaySpruce <jsprucebruce@gmail.com>
2025-05-05 23:14:32 +00:00
Antony
bf42cb3532
Add a viewport UI widget (#17253)
# Objective

Add a viewport widget.

## Solution

- Add a new `ViewportNode` component to turn a UI node into a viewport.
- Add `viewport_picking` to pass pointer inputs from other pointers to
the viewport's pointer.
- Notably, this is somewhat functionally different from the viewport
widget in [the editor
prototype](https://github.com/bevyengine/bevy_editor_prototypes/pull/110/files#L124),
which just moves the pointer's location onto the render target. Viewport
widgets have their own pointers.
  - Care is taken to handle dragging in and out of viewports.
- Add `update_viewport_render_target_size` to update the viewport node's
render target's size if the node size changes.
- Feature gate picking-related viewport items behind
`bevy_ui_picking_backend`.

## Testing

I've been using an example I made to test the widget (and added it as
`viewport_node`):

<details><summary>Code</summary>

```rust
//! A simple scene to demonstrate spawning a viewport widget. The example will demonstrate how to
//! pick entities visible in the widget's view.

use bevy::picking::pointer::PointerInteraction;
use bevy::prelude::*;

use bevy::ui::widget::ViewportNode;
use bevy::{
    image::{TextureFormatPixelInfo, Volume},
    window::PrimaryWindow,
};
use bevy_render::{
    camera::RenderTarget,
    render_resource::{
        Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
    },
};

fn main() {
    App::new()
        .add_plugins((DefaultPlugins, MeshPickingPlugin))
        .add_systems(Startup, test)
        .add_systems(Update, draw_mesh_intersections)
        .run();
}

#[derive(Component, Reflect, Debug)]
#[reflect(Component)]
struct Shape;

fn test(
    mut commands: Commands,
    window: Query<&Window, With<PrimaryWindow>>,
    mut images: ResMut<Assets<Image>>,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // Spawn a UI camera
    commands.spawn(Camera3d::default());

    // Set up an texture for the 3D camera to render to
    let window = window.get_single().unwrap();
    let window_size = window.physical_size();
    let size = Extent3d {
        width: window_size.x,
        height: window_size.y,
        ..default()
    };
    let format = TextureFormat::Bgra8UnormSrgb;
    let image = Image {
        data: Some(vec![0; size.volume() * format.pixel_size()]),
        texture_descriptor: TextureDescriptor {
            label: None,
            size,
            dimension: TextureDimension::D2,
            format,
            mip_level_count: 1,
            sample_count: 1,
            usage: TextureUsages::TEXTURE_BINDING
                | TextureUsages::COPY_DST
                | TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[],
        },
        ..default()
    };
    let image_handle = images.add(image);

    // Spawn the 3D camera
    let camera = commands
        .spawn((
            Camera3d::default(),
            Camera {
                // Render this camera before our UI camera
                order: -1,
                target: RenderTarget::Image(image_handle.clone().into()),
                ..default()
            },
        ))
        .id();

    // Spawn something for the 3D camera to look at
    commands
        .spawn((
            Mesh3d(meshes.add(Cuboid::new(5.0, 5.0, 5.0))),
            MeshMaterial3d(materials.add(Color::WHITE)),
            Transform::from_xyz(0.0, 0.0, -10.0),
            Shape,
        ))
        // We can observe pointer events on our objects as normal, the
        // `bevy::ui::widgets::viewport_picking` system will take care of ensuring our viewport
        // clicks pass through
        .observe(on_drag_cuboid);

    // Spawn our viewport widget
    commands
        .spawn((
            Node {
                position_type: PositionType::Absolute,
                top: Val::Px(50.0),
                left: Val::Px(50.0),
                width: Val::Px(200.0),
                height: Val::Px(200.0),
                border: UiRect::all(Val::Px(5.0)),
                ..default()
            },
            BorderColor(Color::WHITE),
            ViewportNode::new(camera),
        ))
        .observe(on_drag_viewport);
}

fn on_drag_viewport(drag: Trigger<Pointer<Drag>>, mut node_query: Query<&mut Node>) {
    if matches!(drag.button, PointerButton::Secondary) {
        let mut node = node_query.get_mut(drag.target()).unwrap();

        if let (Val::Px(top), Val::Px(left)) = (node.top, node.left) {
            node.left = Val::Px(left + drag.delta.x);
            node.top = Val::Px(top + drag.delta.y);
        };
    }
}

fn on_drag_cuboid(drag: Trigger<Pointer<Drag>>, mut transform_query: Query<&mut Transform>) {
    if matches!(drag.button, PointerButton::Primary) {
        let mut transform = transform_query.get_mut(drag.target()).unwrap();
        transform.rotate_y(drag.delta.x * 0.02);
        transform.rotate_x(drag.delta.y * 0.02);
    }
}

fn draw_mesh_intersections(
    pointers: Query<&PointerInteraction>,
    untargetable: Query<Entity, Without<Shape>>,
    mut gizmos: Gizmos,
) {
    for (point, normal) in pointers
        .iter()
        .flat_map(|interaction| interaction.iter())
        .filter_map(|(entity, hit)| {
            if !untargetable.contains(*entity) {
                hit.position.zip(hit.normal)
            } else {
                None
            }
        })
    {
        gizmos.arrow(point, point + normal.normalize() * 0.5, Color::WHITE);
    }
}
```

</details>

## Showcase


https://github.com/user-attachments/assets/39f44eac-2c2a-4fd9-a606-04171f806dc1

## Open Questions

- <del>Not sure whether the entire widget should be feature gated behind
`bevy_ui_picking_backend` or not? I chose a partial approach since maybe
someone will want to use the widget without any picking being
involved.</del>
- <del>Is `PickSet::Last` the expected set for `viewport_picking`?
Perhaps `PickSet::Input` is more suited.</del>
- <del>Can `dragged_last_frame` be removed in favor of a better dragging
check? Another option that comes to mind is reading `Drag` and `DragEnd`
events, but this seems messier.</del>

---------

Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
2025-05-05 22:57:37 +00:00
Chris Russell
55bb59b844
Stop using ArchetypeComponentId in the executor (#16885)
# Objective

Stop using `ArchetypeComponentId` in the executor. These IDs will grow
even more quickly with relations, and the size may start to degrade
performance.

## Solution

Have systems expose their `FilteredAccessSet<ComponentId>`, and have the
executor use that to determine which systems conflict. This can be
determined statically, so determine all conflicts during initialization
and only perform bit tests when running.

## Testing

I ran many_foxes and didn't see any performance changes. It's probably
worth testing this with a wider range of realistic schedules to see
whether the reduced concurrency has a cost in practice, but I don't know
what sort of test cases to use.

## Migration Guide

The schedule will now prevent systems from running in parallel if there
*could* be an archetype that they conflict on, even if there aren't
actually any. For example, these systems will now conflict even if no
entity has both `Player` and `Enemy` components:
```rust
fn player_system(query: Query<(&mut Transform, &Player)>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy)>) {}
```

To allow them to run in parallel, use `Without` filters, just as you
would to allow both queries in a single system:
```rust
// Either one of these changes alone would be enough
fn player_system(query: Query<(&mut Transform, &Player), Without<Enemy>>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy), Without<Player>>) {}
```
2025-05-05 22:52:44 +00:00
Chris Russell
5f936aefc8
Prevent exclusive systems from being used as observers (#19033)
# Objective

Prevent using exclusive systems as observers. Allowing them is unsound,
because observers are only expected to have `DeferredWorld` access, and
the observer infrastructure will keep pointers that are invalidated by
the creation of `&mut World`.

See
https://github.com/bevyengine/bevy/actions/runs/14778342801/job/41491517847?pr=19011
for a MIRI failure in a recent PR caused by an exclusive system being
used as an observer in a test.

## Solution

Have `Observer::new` panic if `System::is_exclusive()` is true. Document
that method, and methods that call it, as panicking.

(It should be possible to express this in the type system so that the
calls won't even compile, but I did not want to attempt that.)

## Testing

Added a unit test that calls `World::add_observer` with an exclusive
system.
2025-05-05 17:46:25 +00:00
ickshonpe
5e2ecf4178
Text background colors (#18892)
# Objective

Add background colors for text.

Fixes #18889

## Solution

New component `TextBackgroundColor`, add it to any UI `Text` or
`TextSpan` entity to add a background color to its text.
New field on `TextLayoutInfo` `section_rects` holds the list of bounding
rects for each text section.

The bounding rects are generated in `TextPipeline::queue_text` during
text layout, `extract_text_background_colors` extracts the colored
background rects for rendering.

Didn't include `Text2d` support because of z-order issues.

The section rects can also be used to implement interactions targeting
individual text sections.

## Testing
Includes a basic example that can be used for testing:
```
cargo run --example text_background_colors
```
---

## Showcase


![tbcm](https://github.com/user-attachments/assets/e584e197-1a8c-4248-82ab-2461d904a85b)

Using a proportional font with kerning the results aren't so tidy (since
the bounds of adjacent glyphs can overlap) but it still works fine:


![tbc](https://github.com/user-attachments/assets/788bb052-4216-4019-a594-7c1b41164dd5)

---------

Co-authored-by: Olle Lukowski <lukowskiolle@gmail.com>
Co-authored-by: Gilles Henaux <ghx_github_priv@fastmail.com>
2025-05-04 08:18:46 +00:00
ickshonpe
21b62d640b
Change the default visual box for OverflowClipMargin to PaddingBox (#18935)
# Objective

The default should be `OverflowClipBox::PaddingBox` not
`OverflowClipBox::ContentBox`

`padding-box` is the default in CSS. 

## Solution

Set the default to `PaddingBox`.

## Testing

Compare the `overflow` UI example on main vs with this PR. You should
see that on main the outline around the inner node gets clipped. With
this PR by default clipping starts at the inner edge of the border (the
`padding-box`) and the outlines are visible.

Fixes #18934
2025-04-30 21:00:42 +00:00
BD103
6d4a9ad01c
Make some changes to the migration guide recommendations (#18794)
# Objective

- I've worked on the migration guide in the past, so I've written down
some of the conventions and styles I've used.

## Solution

Please read through the descriptions of each commit, which justify the
change! In summary:

- Remove headings from migration guide template by moving style guide to
`migration_guides.md`
- Use parentheses to signal method and function names (`my_func()`
instead of `my_func`)
- Change the guidelines on using bullet points so they're not used for
every single migration guide.
- Remove suggestion to use diff blocks, as they don't syntax-highlight
Rust code.

---------

Co-authored-by: Rob Parrett <robparrett@gmail.com>
Co-authored-by: Miles Silberling-Cook <NthTensor@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-04-10 19:25:56 +00:00
BD103
4f2fa81cef
Add #[deprecated(since = "0.16.0", ...)] to items missing it (#18702)
# Objective

- The `#[deprecated]` attributes supports a `since` field, which
documents in which version an item was deprecated. This field is visible
in `rustdoc`.
- We inconsistently use `since` throughout the project.

For an example of what `since` renders as, take a look at
`ChildOf::get()`:

```rust
/// The parent entity of this child entity.
#[deprecated(since = "0.16.0", note = "Use child_of.parent() instead")]
#[inline]
pub fn get(&self) -> Entity {
    self.0
}
```


![image](https://github.com/user-attachments/assets/2ea5d8c9-2eab-430a-9a1c-421f315ff123)


## Solution

- Add `since = "0.16.0"` to all `#[deprecated]` attributes that do not
already use it.
- Add an example of deprecating a struct with the `since` field in the
migration guide document.

I would appreciate if this could be included in 0.16's release, as its a
low-risk documentation improvement that is valuable for the release, but
I'd understand if this was cut.

## Testing

You can use `cargo doc` to inspect the rendered form of
`#[deprecated(since = "0.16.0", ...)]`.
2025-04-03 17:06:01 +00:00
Zachary Harrold
61f3b3e8f5
Add Advice for Relocations to Migration Guide Template (#18654)
# Objective

Relocations are a fairly common form of migration, and a tabular format
can make reading an otherwise repetitive list much easier. This should
be included in the migration guide template.

## Solution

- Added a dot-point highlighting a tabular format for relocations, with
an explanation.
- Added a dot-point indicating migrations should be written WRT the
currently published version of a crate.
- Fixed some formatting in an adjacent dot-point.

## Testing

- CI
2025-04-01 17:18:59 +00:00
Alice Cecile
4a31d8e91a
Use desired language in migration guide template (#18576)
# Objective

Both reading and writing migration guides is easier when the language is
standardized.

However, migration guide authors don't have clear guidelines for the
tone and phrasing to use.

## Solution

Communicate this information to authors by creating stub text with a
clear and polite standard style.

We could instead write a style guide, but turning style guides into a
writing style is slower and much harder than simply filling in the
blanks. While style guides are a good fit for more free-form writing,
they don't work well for the very mechanical and dry migration guides.

---------

Co-authored-by: Miles Silberling-Cook <NthTensor@users.noreply.github.com>
2025-03-28 16:11:12 +00:00
Miles Silberling-Cook
0a2e183476
Add basic release content tagging workflow (#18568)
# Objective

This PR begins integrating the new releate-content drafting process
(https://github.com/bevyengine/bevy/pull/18427) into our GitHub
workflows. It's similar to what we had before: Messages are posted to
PRs tagged with `M-Needs-Release-Note` or `M-Needs-Migration-Guide`
asking them to add the required material and linking to the
instructions. These messages do not trigger if the PR already has
modified files in the `release-notes` or `migration-guides` directories
(respectively).

I have also re-arranged and content slightly (to remove the need for a
directory with the current version number), tweaked the language, and
switched the templates to use the [standard markdown frontmatter
format](https://jekyllrb.com/docs/front-matter/).

## Reviewer Questions

+ Do we want to add a CI rule actually requiring tagged PRs to
create/modify files in the correct directories, or is the message prompt
enough?
+ Do we want to add a CI rule to lint the metadata, for example to
enforce that the PR number is included in the files it modifies?
2025-03-27 17:46:39 +00:00