# Objective
- Bevy currently has lot of invalid intra-doc links, let's fix them!
- Also make CI test them, to avoid future regressions.
- Helps with #1983 (but doesn't fix it, as there could still be explicit
links to docs.rs that are broken)
## Solution
- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
# Objective
Fixes#14248 and other URL issues.
## Solution
- Describe the solution used to achieve the objective above.
Removed the random #s in the URL. Led users to the wrong page. For
example, https://bevyengine.org/learn/errors/#b0003 takes users to
https://bevyengine.org/learn/errors/introduction, which is not the right
page. Removing the #s fixes it.
## Testing
- Did you test these changes? If so, how?
I pasted the URL into my address bar and it took me to the right place.
- Are there any parts that need more testing?
No
# Objective
- Often in games you will want to create chains of systems that modify
some event. For example, a chain of damage systems that handle a
DamageEvent and modify the underlying value before the health system
finally consumes the event. Right now this requires either:
* Using a component added to the entity
* Consuming and refiring events
Neither is ideal when really all we want to do is read the events value,
modify it, and write it back.
## Solution
- Create an EventMutator class similar to EventReader but with ResMut<T>
and iterators that return &mut so that events can be mutated.
## Testing
- I replicated all the existing tests for EventReader to make sure
behavior was the same (I believe) and added a number of tests specific
to testing that 1) events can actually be mutated, and that 2)
EventReader sees changes from EventMutator for events it hasn't already
seen.
## Migration Guide
Users currently using `ManualEventReader` should use `EventCursor`
instead. `ManualEventReader` will be removed in Bevy 0.16. Additionally,
`Events::get_reader` has been replaced by `Events::get_cursor`.
Users currently directly accessing the `Events` resource for mutation
should move to `EventMutator` if possible.
---------
Co-authored-by: poopy <gonesbird@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Bump version after release
This PR has been auto-generated
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
# Objective
Fixes https://github.com/bevyengine/bevy/issues/13972
## Solution
Added 3 new attributes to the `Component` macro.
## Testing
Added `component_hook_order_spawn_despawn_with_macro_hooks`, that makes
the same as `component_hook_order_spawn_despawn` but uses a struct, that
defines it's hooks with the `Component` macro.
---
---------
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
The bounds for query iterators are quite intimidating.
## Solution
With Rust 1.79, [associated type
bounds](https://github.com/rust-lang/rust/pull/122055/) stabilized,
which can simplify the bounds slightly.
# Objective
Add ability to de-register events from the EventRegistry (and the
associated World).
The initial reasoning relates to retaining support for Event hot
reloading in `dexterous_developer`.
## Solution
Add a `deregister_events<T: Event>(&mut world)` method to the
`EventRegistry` struct.
## Testing
Added an automated test that verifies the event registry adds and
removes `Events<T>` from the world.
---------
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
- Fixes a correctness error introduced in
https://github.com/bevyengine/bevy/pull/14013 ...
## Solution
I've been playing around a lot of with the access code and I realized
that I introduced a soundness error when trying to simplify the code.
When we have a `Or<(With<A>, With<B>)>` filter, we cannot call
```
let mut intermediate = FilteredAccess::default();
$name::update_component_access($name, &mut intermediate);
_new_access.append_or(&intermediate);
```
because that's just equivalent to adding the new components as `Or`
clauses.
For example if the existing `filter_sets` was `vec![With<C>]`, we would
then get `vec![With<C>, With<A>, With<B>]` which translates to `A or B
or C`.
Instead what we want is `(A and B) or (A and C)`, so we need to have
each new OR clause compose with the existing access like so:
```
let mut intermediate = _access.clone();
// if we previously had a With<C> in the filter_set, this will become `With<C> AND With<A>`
$name::update_component_access($name, &mut intermediate);
_new_access.append_or(&intermediate);
```
## Testing
- Added a unit test that is broken in main, but passes in this PR
# Objective
`StaticSystemParam` should delegate all `SystemParam` methods to the
inner param, but it looks like it was missed when the new `queue()`
method was added in #10839.
## Solution
Implement `StaticSystemParam::queue()` to delegate to the inner param.
# Objective
When using combinators such as `EntityCommand::with_entity` to build
commands, it can be easy to forget to apply that command, leading to
dead code. In many cases this doesn't even lead to an unused variable
warning, which can make these mistakes difficult to track down
## Solution
Annotate the method with `#[must_use]`
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
The trait method `with_entity` is used to add an `EntityCommand` to the
command queue. Currently this method returns `WithEntity<C>` which pairs
a command with an `Entity`. By replacing this explicit type with an
opaque type, implementors can override this default implementation by
returning a custom command or closure that does the same thing with a
lower memory footprint.
# Solution
Return an opaque type from the method. As a bonus this file is now
cleaner without the `WithEntity` boilerplate
# Objective
Fixes https://github.com/bevyengine/bevy/issues/13993
PR inspired by https://github.com/bevyengine/bevy/pull/14007 to
accomplish the same thing, but maybe in a clearer fashion.
@Gingeh feel free to take my changes and add them to your PR, I don't
want to steal any credit
---------
Co-authored-by: Gingeh <39150378+Gingeh@users.noreply.github.com>
Co-authored-by: Bob Gardner <rgardner@inworld.ai>
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
# Objective
#12469 changed the `Debug` impl for `Entity`, making sure it's actually
accurate for debugging. To ensure that its can still be readily logged
in error messages and inspectors, this PR added a more concise and
human-friendly `Display` impl.
However, users found this form too verbose: the `to_bits` information
was unhelpful and too long. Fixes#13980.
## Solution
- Don't include `Entity::to_bits` in the `Display` implementation for
`Entity`. This information can readily be accessed and logged for users
who need it.
- Also clean up the implementation of `Display` for `DebugName`,
introduced in https://github.com/bevyengine/bevy/pull/13760, to simply
use the new `Display` impl (since this was the desired format there).
## Testing
I've updated an existing test to verify the output of `Entity::display`.
---------
Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
# Objective
- Fix issue #13821
## Solution
- Rewrote the test to ensure that it actually tests the functionality
correctly. Then made the par_read function correctly change the values
of self.reader.last_event_count.
## Testing
- Rewrote the test for par_read to run the system schedule twice,
checking the output each time
---------
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
fixes#13944
I literally just added `Did you forget to call SystemState::apply?` to
the error message. I tested it with the code snipped from the Issue and
yeah it works
# Objective
`with_event` will result in unsafe casting of event data of the given
type to the type expected by the Observer system. This is inherently
unsafe.
## Solution
Flag `Observer::with_event` and `ObserverDescriptor::with_events` as
unsafe. This will not affect normal workflows as `with_event` is
intended for very specific (largely internal) use cases.
This _should_ be backported to 0.14 before release.
---
## Changelog
- `Observer::with_event` is now unsafe.
- Rename `ObserverDescriptor::with_triggers` to
`ObserverDescriptor::with_events` and make it unsafe.
# Objective
Fixes#13933.
## Solution
Changed the return type.
## Testing
Fixed and reused the pre-existing tests for `inspect_entity`.
---
## Migration Guide
- `World::inspect_entity` now returns an `Iterator` instead of a `Vec`.
If you need a `Vec`, immediately collect the iterator:
`world.inspect_entity(entity).collect<Vec<_>>()`
# Objective
Fixes#13917
## Solution
Changed `IntoSystemSetConfigs::chain_ignore_deferred`'s return type from
`SystemConfigs` to `SystemSetConfigs`
## Testing
Tried to run the `ecs_guide` example, where `chain` method is replaced
by `chain_ignore_deferred` method
---
# Objective
- Fix a typo in documentation for `Query::single_mut`
## Solution
- Change `item` to `items`
## Testing
- I built the documentation and it looked fine.
- Since this only affects a doc comment, no further testing should be
necessary.
---
## Changelog
> This section is optional. If this was a trivial fix, or has no
externally-visible impact, you can delete this section.
- Fixed a typo in the documentation for Query.
# Objective
While writing code for the `bevy_ecs` I noticed we were using a
unnecessarily stable sort to sort component ids
## Solution
- Sort component ids with a unstable sort
- Comb the bevy_ecs crate for any other obvious inefficiencies.
- Don't clone component vectors when inserting an archetype.
## Testing
I ran `cargo test -p bevy_ecs`. Everything else I leave to CI.
## Profiling
I measured about a 1% speed increase when spawning entities directly
into a world. Since the difference is so small (and might just be noise)
I didn't bother to figure out which of change if any made the biggest
difference.
<details>
<summary> Tracy data </summary>
Yellow is this PR. Red is the commit I branched from.
</details>
<details>
<summary>Methodology</summary>
I created a system that spawn a 1000 entities each with the same 30
components each frame, and then I measured it's run time. The unusually
high number of components was chosen because the standard library [will
use a insertion sort for slices under 20
elements](0de24a5177/library/core/src/slice/sort.rs (L1048-L1049)).
This holds for both stable and unstable sorts.
</details>
# Objective
- Provide an expressive way to register dynamic behavior in response to
ECS changes that is consistent with existing bevy types and traits as to
provide a smooth user experience.
- Provide a mechanism for immediate changes in response to events during
command application in order to facilitate improved query caching on the
path to relations.
## Solution
- A new fundamental ECS construct, the `Observer`; inspired by flec's
observers but adapted to better fit bevy's access patterns and rust's
type system.
---
## Examples
There are 3 main ways to register observers. The first is a "component
observer" that looks like this:
```rust
world.observe(|trigger: Trigger<OnAdd, Transform>, query: Query<&Transform>| {
let transform = query.get(trigger.entity()).unwrap();
});
```
The above code will spawn a new entity representing the observer that
will run it's callback whenever the `Transform` component is added to an
entity. This is a system-like function that supports dependency
injection for all the standard bevy types: `Query`, `Res`, `Commands`
etc. It also has a `Trigger` parameter that provides information about
the trigger such as the target entity, and the event being triggered.
Importantly these systems run during command application which is key
for their future use to keep ECS internals up to date. There are similar
events for `OnInsert` and `OnRemove`, and this will be expanded with
things such as `ArchetypeCreated`, `TableEmpty` etc. in follow up PRs.
Another way to register an observer is an "entity observer" that looks
like this:
```rust
world.entity_mut(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Entity observers run whenever an event of their type is triggered
targeting that specific entity. This type of observer will de-spawn
itself if the entity (or entities) it is observing is ever de-spawned so
as to not leave dangling observers.
Entity observers can also be spawned from deferred contexts such as
other observers, systems, or hooks using commands:
```rust
commands.entity(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Observers are not limited to in built event types, they can be used with
any type that implements `Event` (which has been extended to implement
Component). This means events can also carry data:
```rust
#[derive(Event)]
struct Resize { x: u32, y: u32 }
commands.entity(entity).observe(|trigger: Trigger<Resize>, query: Query<&mut Size>| {
let event = trigger.event();
// ...
});
// Will trigger the observer when commands are applied.
commands.trigger_targets(Resize { x: 10, y: 10 }, entity);
```
You can also trigger events that target more than one entity at a time:
```rust
commands.trigger_targets(Resize { x: 10, y: 10 }, [e1, e2]);
```
Additionally, Observers don't _need_ entity targets:
```rust
app.observe(|trigger: Trigger<Quit>| {
})
commands.trigger(Quit);
```
In these cases, `trigger.entity()` will be a placeholder.
Observers are actually just normal entities with an `ObserverState` and
`Observer` component! The `observe()` functions above are just shorthand
for:
```rust
world.spawn(Observer::new(|trigger: Trigger<Resize>| {});
```
This will spawn the `Observer` system and use an `on_add` hook to add
the `ObserverState` component.
Dynamic components and trigger types are also fully supported allowing
for runtime defined trigger types.
## Possible Follow-ups
1. Deprecate `RemovedComponents`, observers should fulfill all use cases
while being more flexible and performant.
2. Queries as entities: Swap queries to entities and begin using
observers listening to archetype creation triggers to keep their caches
in sync, this allows unification of `ObserverState` and `QueryState` as
well as unlocking several API improvements for `Query` and the
management of `QueryState`.
3. Trigger bubbling: For some UI use cases in particular users are
likely to want some form of bubbling for entity observers, this is
trivial to implement naively but ideally this includes an acceleration
structure to cache hierarchy traversals.
4. All kinds of other in-built trigger types.
5. Optimization; in order to not bloat the complexity of the PR I have
kept the implementation straightforward, there are several areas where
performance can be improved. The focus for this PR is to get the
behavior implemented and not incur a performance cost for users who
don't use observers.
I am leaving each of these to follow up PR's in order to keep each of
them reviewable as this already includes significant changes.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
As discovered in
https://github.com/Leafwing-Studios/leafwing-input-manager/issues/538,
there appears to be some real weirdness going on in how event updates
are processed between Bevy 0.13 and Bevy 0.14.
To identify the cause and prevent regression, I've added tests to
validate the intended behavior.
My initial suspicion was that this would be fixed by
https://github.com/bevyengine/bevy/pull/13762, but that doesn't seem to
be the case.
Instead, events appear to never be updated at all when using `bevy_app`
by itself. This is part of the problem resolved by
https://github.com/bevyengine/bevy/pull/11528, and introduced by
https://github.com/bevyengine/bevy/pull/10077.
After some investigation, it appears that `signal_event_update_system`
is never added using a bare-bones `App`, and so event updates are always
skipped.
This can be worked around by adding your own copy to a
later-in-the-frame schedule, but that's not a very good fix.
## Solution
Ensure that if we're not using a `FixedUpdate` schedule, events are
always updated every frame.
To do this, I've modified the logic of `event_update_condition` and
`event_update_system` to clearly and correctly differentiate between the
two cases: where we're waiting for a "you should update now" signal and
where we simply don't care.
To encode this, I've added the `ShouldUpdateEvents` enum, replacing a
simple `bool` in `EventRegistry`'s `needs_update` field.
Now, both tests pass as expected, without having to manually add a
system!
## Testing
I've written two parallel unit tests to cover the intended behavior:
1. Test that `iter_current_update_events` works as expected in
`bevy_ecs`.
2. Test that `iter_current_update_events` works as expected in
`bevy_app`
I've also added a test to verify that event updating works correctly in
the presence of a fixed main schedule, and a second test to verify that
fixed updating works at all to help future authors narrow down failures.
## Outstanding
- [x] figure out why the `bevy_app` version of this test fails but the
`bevy_ecs` version does not
- [x] figure out why `EventRegistry::run_updates` isn't working properly
- [x] figure out why `EventRegistry::run_updates` is never getting
called
- [x] figure out why `event_update_condition` is always returning false
- [x] figure out why `EventRegistry::needs_update` is always false
- [x] verify that the problem is a missing `signal_events_update_system`
---------
Co-authored-by: Mike <mike.hsu@gmail.com>
…izer (#13442)"
This reverts commit 5cfb063d4a.
- This PR broke bevy-trait-query, which needs to be able to write a
resource in init_state. See #13798 for more details.
- Note this doesn't fix everything as transmutes for bevy-trait-query
will still be broken,. But the current usage in that crate is UB, so we
need to find another solution.
# Objective
- Split the bevy_ecs::events module so it's easier to work with
## Solution
- Split the event.rs file across multiple files, made sure all tests
passed, and exports from the module were the same as previous
## Testing
- All automated tests pass.
Fixes#13758.
# Objective
Calling `update` on the main app already calls `clear_trackers`. Calling
it again in `SubApps::update` caused RemovedCompenet Events to be
cleared earlier than they should be.
## Solution
- Don't call clear_trackers an extra time.
## Testing
I manually tested the fix with this unit test:
```
#[cfg(test)]
mod test {
use crate::core::{FrameCount, FrameCountPlugin};
use crate::prelude::*;
#[test]
fn test_next_frame_removal() {
#[derive(Component)]
struct Foo;
#[derive(Resource)]
struct RemovedCount(usize);
let mut app = App::new();
app.add_plugins(FrameCountPlugin);
app.add_systems(Startup, |mut commands: Commands| {
for _ in 0..100 {
commands.spawn(Foo);
}
commands.insert_resource(RemovedCount(0));
});
app.add_systems(First, |counter: Res<FrameCount>| {
println!("Frame {}:", counter.0)
});
fn detector_system(
mut removals: RemovedComponents<Foo>,
foos: Query<Entity, With<Foo>>,
mut removed_c: ResMut<RemovedCount>,
) {
for e in removals.read() {
println!(" Detected removed Foo component for {e:?}");
removed_c.0 += 1;
}
let c = foos.iter().count();
println!(" Total Foos: {}", c);
assert_eq!(c + removed_c.0, 100);
}
fn deleter_system(foos: Query<Entity, With<Foo>>, mut commands: Commands) {
foos.iter().next().map(|e| {
commands.entity(e).remove::<Foo>();
});
}
app.add_systems(Update, (detector_system, deleter_system).chain());
app.update();
app.update();
app.update();
app.update();
}
}
```
# Objective
There were some issues with the `serialize` feature:
- `bevy_app` had a `serialize` feature and a dependency on `serde` even
there is no usage of serde at all inside `bevy_app`
- the `bevy_app/serialize` feature enabled `bevy_ecs/serde`, which is
strange
- `bevy_internal/serialize` did not enable `bevy_app/serialize` so there
was no way of serializing an Entity in bevy 0.14
## Solution
- Remove `serde` and `bevy_app/serialize`
- Add a `serialize` flag on `bevy_ecs` that enables `serde`
- ` bevy_internal/serialize` now enables `bevy_ecs/serialize`
# Objective
- My attempt at fulfilling #13629.
## Solution
Renames the `and_then` / `or_else` run condition methods to `and` /
`or`, respectively.
Extends the run conditions API to include a suite of binary logical
operators:
- `and`
- `or`
- `nand`
- `nor`
- `xor`
- `xnor`
## Testing
- Did you test these changes? If so, how?
- The test **run_condition_combinators** was extended to include the
added run condition combinators. A **double_counter** system was added
to test for combinators running on even count cycles.
- Are there any parts that need more testing?
- I'm not too sure how I feel about the "counter" style of testing but I
wanted to keep it consistent. If it's just a unit test I would prefer
simply to just assert `true` == _combinator output_ or `false` ==
_combinator output_ .
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Nothing too specific. The added methods should be equivalent to the
logical operators they are analogous to (`&&` , `||`, `^`, `!`).
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
- Should not be relevant, I'm using Windows.
## Changelog
- What changed as a result of this PR?
- The run conditions API.
- If applicable, organize changes under "Added", "Changed", or "Fixed"
sub-headings
- Changed:
- `and_then` run condition combinator renamed to simply `and`
- `or_else` run condition combinator renamed to simply `or`
- Added:
- `nand` run condition combinator.
- `nor` run condition combinator.
- `xor` run condition combinator.
- `xnor` run condition combinator.
## Migration Guide
- The `and_then` run condition method has been replaced with the `and`
run condition method.
- The `or_else` run condition method has been replaced with the `or` run
condition method.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Andres O. Vela <andresovela@users.noreply.github.com>
# Objective
The `EntityCommands::despawn` method was previously changed from
panicking behavior to a warning, but the docs continue to state that it
panics.
## Solution
- Removed panic section, copied warning blurb from `World::despawn`
- Adds a similar warning blurb to
`DespawnRecursiveExt::despawn_recursive` and
`DespawnRecursiveExt::despawn_descendants`
# Objective
- Fixes#13703
## Solution
- Added `mappings` to the `EntityMapper` trait, which returns an
iterator over currently tracked `Entity` to `Entity` mappings.
- Added `DynEntityMapper` as an [object
safe](https://doc.rust-lang.org/reference/items/traits.html#object-safety)
alternative to `EntityMapper`.
- Added `assert_object_safe` as a helper for ensuring traits are object
safe.
## Testing
- Added new unit test `entity_mapper_iteration` which tests the
`SceneEntityMapper` implementation of `EntityMapper::mappings`.
- Added unit tests to ensure `DynEntityMapper`, `DynEq` and `DynHash`
are object safe.
- Passed CI on my Windows 10 development environment
---
## Changelog
- Added `mappings` to `EntityMapper` trait.
## Migration Guide
- If you are implementing `EntityMapper` yourself, you can use the below
as a stub implementation:
```rust
fn mappings(&self) -> impl Iterator<Item = (Entity, Entity)> {
unimplemented!()
}
```
- If you were using `EntityMapper` as a trait object (`dyn
EntityMapper`), instead use `dyn DynEntityMapper` and its associated
methods.
## Notes
- The original issue proposed returning a `Vec` from `EntityMapper`
instead of an `impl Iterator` to preserve its object safety. This is a
simpler option, but also forces an allocation where it isn't strictly
needed. I've opted for this split into `DynEntityMapper` and
`EntityMapper` as it's been done several times across Bevy already, and
provides maximum flexibility to users.
- `assert_object_safe` is an empty function, since the assertion
actually happens once you try to use a `dyn T` for some trait `T`. I
have still added this function to clearly document what object safety is
within Bevy, and to create a standard way to communicate that a given
trait must be object safe.
- Other traits should have tests added to ensure object safety, but I've
left those off to avoid cluttering this PR further.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Add slice based variants of existing `get_many_entities` functions on
`World`. This allows for a collection of entries to be looked up mutably
or immutably instead of requiring a compile time constant number.
## Solution
We just take slices and return Vectors.
the following functions have been added:
- `get_many_entities_dynamic`
- `get_many_entities_dynamic_mut`
- `get_many_entities_from_set_mut`
## Testing
- Doc tests, which pass when run through Miri
# Objective
- Fix#10958 by performing entity mapping on the entities inside of
resources.
## Solution
- Resources can reflect(MapEntitiesResource) and impl MapEntities to get
access to the mapper during the world insert of the scene.
## Testing
- A test resource_entity_map_maps_entities confirms the desired
behavior.
## Changelog
- Added reflect(MapEntitiesResource) for mapping entities on Resources
in a DynamicScene.
fixes 10958
# Objective
- Follow-up on some changes in #11498
- Unblock using `Identifier` to replace `ComponentId` internals.
## Solution
- Implement the same `Reflect` impls from `Entity` onto `Identifier` as
they share same/similar purposes,
## Testing
- No compile errors. Currently `Identifier` has no serialization impls,
so there's no need to test a serialization/deserialization roundtrip to
ensure correctness.
---
## Changelog
### Added
- Reflection implementations on `Identifier`.
# Objective
`SceneEntityMapper` seems like it could be generally useful.
## Solution
Allow end users to call `SceneEntityMapper::new` and
`SceneEntityMapper::finish`.
# Objective
Adds capability to clear all components on an entity without de-spawning
said entity.
## Testing
The function calls `remove_by_id` on every component in the entity
archetype - wasn't sure if it's worth going out of our way to create a
test for this considering `remove_by_id` is already unit tested.
---
## Changelog
Added `clear` function to `EntityWorldMut` which removes all components
on an entity.
## Migration Guide
N/A
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
In #13343, `WorldQuery::get_state` was constrained from `&World` as the
argument to `&Components`, but `WorldQuery::init_state` hasn't yet been
changed from `&mut World` to match.
Fixes#13358
## Solution
Create a wrapper around `&mut Components` and `&mut Storages` that can
be obtained from `&mut World` with a `component_initializer` method.
This new `ComponentInitializer` re-exposes the API on `&mut Components`
minus the `&mut Storages` parameter where it was present. For the
`&Components` API, it simply derefs to its `components` field.
## Changelog
### Added
The `World::component_initializer` method.
The `ComponentInitializer` struct that re-exposes `Components` API.
### Changed
`WorldQuery::init_state` now takes `&mut ComponentInitializer` instead
of `&mut World`.
## Migration Guide
Instead of passing `&mut World` to `WorldQuery::init_state` directly,
pass in a mutable reference to the struct returned from
`World::component_initializer`.
Currently, either an `EntityRef` or `EntityMut` is required in order to
reflect a component on an entity. This can, however, be generalized to
`FilteredEntityRef` and `FilteredEntityMut`, which are versions of
`EntityRef` and `EntityMut` that restrict the components that can be
accessed. This is useful because dynamic queries yield
`FilteredEntityRef` and `FilteredEntityMut` rows when iterated over.
This commit changes `ReflectComponent::contains()`,
`ReflectComponent::reflect()`, and `ReflectComponent::reflect_mut()` to
take an `Into<FilteredEntityRef>` (in the case of `contains()` and
`reflect()`) and `Into<FilteredEntityMut>` (in the case of
`reflect_mut()`). Fortunately, `EntityRef` and `EntityMut` already
implement the corresponding trait, so nothing else has to be done to the
public API. Note that in order to implement
`ReflectComponent::reflect_mut()` properly, an additional method
`FilteredEntityMut::into_mut()` was required, to match the one on
`EntityMut`.
I ran into this when attempting to implement `QUERY` in the Bevy Remote
Protocol when trying to iterate over rows of dynamic queries and fetch
the associated components without unsafe code. There were other
potential ways to work around this problem, but they required either
reimplementing the query logic myself instead of using regular Bevy
queries or storing entity IDs and then issuing another query to fetch
the associated `EntityRef`. Both of these seemed worse than just
improving the `reflect()` function.
## Migration Guide
* `ReflectComponent::contains`, `ReflectComponent::reflect`, and
`ReflectComponent::reflect_mut` now take `FilteredEntityRef` (in the
case of `contains()` and `reflect()`) and `FilteredEntityMut` (in the
case of `reflect_mut()`) parameters. `FilteredEntityRef` and
`FilteredEntityMut` have very similar APIs to `EntityRef` and
`EntityMut` respectively, but optionally restrict the components that
can be accessed.
# Objective
- `FilteredEntity{Ref,Mut}` various `get` methods never checked that the
given component was present on the entity, only the access allowed
reading/writing them, which is always the case when it is constructed
from a `EntityRef`/`EntityMut`/`EntityWorldMut` (and I guess can also
happen with queries containing `Option<T>` that get transmuted).
- In those cases the various `get` methods were calling
`debug_checked_unwrap` on `None`s, which is UB when debug assertions are
not enabled;
- The goal is thus to fix this soundness issue.
## Solution
- Don't call `debug_checked_unwrap` on those `None` and instead
`flatten` them.
## Testing
- This PR includes regression tests for each combination of
`FilteredEntityRef`/`FilteredEntityMut` and component
present/not-present. The two tests for the not-present cases fail on
`main` but success with this PR changes.
# Objective
- Prevent the case where a hook/observer is triggered but the source
entity/component no longer exists
## Solution
- Re-order command application such that all hooks/observers that are
notified will run before any have a chance to invalidate the result.
## Testing
Updated relevant tests in `bevy_ecs`, all other tests pass.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
The current query iterators cannot be used in positions with a `Debug`
bound.
F.e. when they are packaged in `Result` in the error position, `expect`
cannot be called on them.
Required for `QueryManyIter::entities_all_unique` in #13477.
## Solution
Add simple `Debug` impls that print the query iterator names.
## Changelog
`QueryIter`, `QueryManyIter`, `QueryCombinationIter`, and
`QuerySortedIter` now implement `Debug`.
# Objective
While reviewing the other open hooks-related PRs, I found that the docs
on the `ComponentHooks` struct itself didn't give enough information
about how and why the feature could be used.
## Solution
1. Clean up the docs to add additional context.
2. Add a doc test demonstrating simple usage.
## Testing
The doc test passes locally.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
# Objective
- Implement a general purpose mechanism for building `SystemParam`.
- Unblock the usage of dynamic queries in regular systems.
## Solution
- Implement a `SystemBuilder` type.
## Examples
Here are some simple test cases for the builder:
```rust
fn local_system(local: Local<u64>) -> u64 {
*local
}
fn query_system(query: Query<()>) -> usize {
query.iter().count()
}
fn multi_param_system(a: Local<u64>, b: Local<u64>) -> u64 {
*a + *b + 1
}
#[test]
fn local_builder() {
let mut world = World::new();
let system = SystemBuilder::<()>::new(&mut world)
.builder::<Local<u64>>(|x| *x = 10)
.build(local_system);
let result = world.run_system_once(system);
assert_eq!(result, 10);
}
#[test]
fn query_builder() {
let mut world = World::new();
world.spawn(A);
world.spawn_empty();
let system = SystemBuilder::<()>::new(&mut world)
.builder::<Query<()>>(|query| {
query.with::<A>();
})
.build(query_system);
let result = world.run_system_once(system);
assert_eq!(result, 1);
}
#[test]
fn multi_param_builder() {
let mut world = World::new();
world.spawn(A);
world.spawn_empty();
let system = SystemBuilder::<()>::new(&mut world)
.param::<Local<u64>>()
.param::<Local<u64>>()
.build(multi_param_system);
let result = world.run_system_once(system);
assert_eq!(result, 1);
}
```
This will be expanded as this PR is iterated.
# Objective
Currently, a query iterator can be collected into a `Vec` and sorted,
but this can be quite unwieldy, especially when many `Component`s are
involved. The `itertools` crate helps somewhat, but the need to write a
closure over all of `QueryData`
can sometimes hurt ergonomics, anywhere from slightly to strongly. A key
extraction function only partially helps, as `sort_by_key` does not
allow returning non-`Copy` data. `sort_by` does not suffer from the
`Copy` restriction, but now the user has to write out a `cmp` function
over two `QueryData::Item`s when it could have just been handled by the
`Ord` impl for the key.
`sort` requires the entire `Iterator` Item to be `Ord`, which is rarely
usable without manual helper functionality. If the user wants to hide
away unused components with a `..` range, they need to track item tuple
order across their function. Mutable `QueryData` can also introduce
further complexity.
Additionally, sometimes users solely include `Component`s /`Entity` to
guarantee iteration order.
For a user to write a function to abstract away repeated sorts over
various `QueryData` types they use would require reaching for the
`all_tuples!` macro, and continue tracking tuple order afterwards.
Fixes https://github.com/bevyengine/bevy/issues/1470.
## Solution
Custom sort methods on `QueryIter`, which take a query lens as a generic
argument, like `transmute_lens` in `Query`.
This allows users to choose what part of their queries they pass to
their sort function calls, serving as a kind of "key extraction
function" before the sort call. F.e. allowing users to implement `Ord`
for a Component, then call `query.iter().sort::<OrdComponent>()`
This works independent of mutability in `QueryData`, `QueryData` tuple
order, or the underlying `iter/iter_mut` call.
Non-`Copy` components could also be used this way, an internal
`Arc<usize>` being an example.
If `Ord` impls on components do not suffice, other sort methods can be
used. Notably useful when combined with `EntityRef` or `EntityMut`.
Another boon from using underlying `transmute` functionality, is that
with the [allowed
transmutes](http://dev-docs.bevyengine.org/bevy/ecs/prelude/struct.Query.html#allowed-transmutes),
it is possible to sort a `Query` with `Entity` even if it wasn't
included in the original `Query`.
The additional generic parameter on the methods other than `sort` and
`sort_unstable` currently cannot be removed due to Rust limitations,
however their types can be inferred.
The new methods do not conflict with the `itertools` sort methods, as
those use the "sorted" prefix.
This is implemented barely touching existing code. That change to
existing code being that `QueryIter` now holds on to the reference to
`UnsafeWorldCell` that is used to initialize it.
A lens query is constructed with `Entity` attached at the end, sorted,
and turned into an iterator. The iterator maps away the lens query,
leaving only an iterator of `Entity`, which is used by `QuerySortedIter`
to retrieve the actual items.
`QuerySortedIter` resembles a combination of `QueryManyIter` and
`QueryIter`, but it uses an entity list that is guaranteed to contain
unique entities, and implements `ExactSizeIterator`,
`DoubleEndedIterator`, `FusedIterator` regardless of mutability or
filter kind (archetypal/non-archetypal).
The sort methods are not allowed to be called after `next`, and will
panic otherwise. This is checked using `QueryIterationCursor` state,
which is unique on initialization. Empty queries are an exception to
this, as they do not return any item in the first place.
That is because tracking how many iterations have already passed would
require regressing either normal query iteration a slight bit, or sorted
iteration by a lot. Besides, that would not be the intended use of these
methods.
## Testing
To ensure that `next` being called before `sort` results in a panic, I
added some tests. I also test that empty `QueryIter`s do not exhibit
this restriction.
The query sorts test checks for equivalence to the underlying sorts.
This change requires that `Query<(Entity, Entity)>` remains legal, if
that is not already guaranteed, which is also ensured by the
aforementioned test.
## Next Steps
Implement the set of sort methods for `QueryManyIter` as well.
- This will mostly work the same, other than needing to return a new
`QuerySortedManyIter` to account for iteration
over lists of entities that are not guaranteed to be unique. This new
query iterator will need a bit of internal restructuring
to allow for double-ended mutable iteration, while not regressing
read-only iteration.
The implementations for each pair of
- `sort`, `sort_unstable`,
- `sort_by`, sort_unstable_by,
- `sort_by_key,` `sort_by_cached_key`
are the same aside from the panic message and the sort call, so they
could be merged with an inner function.
That would require the use of higher-ranked trait bounds on
`WorldQuery::Item<'1>`, and is unclear to me whether it is currently
doable.
Iteration in QuerySortedIter might have space for improvement.
When sorting by `Entity`, an `(Entity, Entity)` lens `QueryData` is
constructed, is that worth remedying?
When table sorts are implemented, a fast path could be introduced to
these sort methods.
## Future Possibilities
Implementing `Ord` for EntityLocation might be useful.
Some papercuts in ergonomics can be improved by future Rust features:
- The additional generic parameter aside from the query lens can be
removed once this feature is stable:
`Fn -> impl Trait` (`impl Trait` in `Fn` trait return position)
- With type parameter defaults, the query lens generic can be defaulted
to `QueryData::Item`, allowing the sort methods
to look and behave like `slice::sort` when no query lens is specified.
- With TAIT, the iterator generic on `QuerySortedIter` and thus the huge
visible `impl Iterator` type in the sort function
signatures can be removed.
- With specialization, the bound on `L` could be relaxed to `QueryData`
when the underlying iterator is mutable.
## Changelog
Added `sort`, `sort_unstable`, `sort_by`, `sort_unstable_by`,
`sort_by_key`, `sort_by_cached_key` to `QueryIter`.
# Objective
- Fixes#12377
## Solution
Added simple `#[diagnostic::on_unimplemented(...)]` attributes to some
critical public traits providing a more approachable initial error
message. Where appropriate, a `note` is added indicating that a `derive`
macro is available.
## Examples
<details>
<summary>Examples hidden for brevity</summary>
Below is a collection of examples showing the new error messages
produced by this change. In general, messages will start with a more
Bevy-centric error message (e.g., _`MyComponent` is not a `Component`_),
and a note directing the user to an available derive macro where
appropriate.
### Missing `#[derive(Resource)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct MyResource;
fn main() {
App::new()
.insert_resource(MyResource)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `MyResource` is not a `Resource`
--> examples/app/empty.rs:7:26
|
7 | .insert_resource(MyResource)
| --------------- ^^^^^^^^^^ invalid `Resource`
| |
| required by a bound introduced by this call
|
= help: the trait `Resource` is not implemented for `MyResource`
= note: consider annotating `MyResource` with `#[derive(Resource)]`
= help: the following other types implement trait `Resource`:
AccessibilityRequested
ManageAccessibilityUpdates
bevy::bevy_a11y::Focus
DiagnosticsStore
FrameCount
bevy::prelude::State<S>
SystemInfo
bevy::prelude::Axis<T>
and 141 others
note: required by a bound in `bevy::prelude::App::insert_resource`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:419:31
|
419 | pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self {
| ^^^^^^^^ required by this bound in `App::insert_resource`
```
</details>
### Putting A `QueryData` in a `QueryFilter` Slot
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Component)]
struct A;
#[derive(Component)]
struct B;
fn my_system(_query: Query<&A, &B>) {}
fn main() {
App::new()
.add_systems(Update, my_system)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `&B` is not a valid `Query` filter
--> examples/app/empty.rs:9:22
|
9 | fn my_system(_query: Query<&A, &B>) {}
| ^^^^^^^^^^^^^ invalid `Query` filter
|
= help: the trait `QueryFilter` is not implemented for `&B`
= help: the following other types implement trait `QueryFilter`:
With<T>
Without<T>
bevy::prelude::Or<()>
bevy::prelude::Or<(F0,)>
bevy::prelude::Or<(F0, F1)>
bevy::prelude::Or<(F0, F1, F2)>
bevy::prelude::Or<(F0, F1, F2, F3)>
bevy::prelude::Or<(F0, F1, F2, F3, F4)>
and 28 others
note: required by a bound in `bevy::prelude::Query`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\query.rs:349:51
|
349 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> {
| ^^^^^^^^^^^ required by this bound in `Query`
```
</details>
### Missing `#[derive(Component)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct A;
fn my_system(mut commands: Commands) {
commands.spawn(A);
}
fn main() {
App::new()
.add_systems(Startup, my_system)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `A` is not a `Bundle`
--> examples/app/empty.rs:6:20
|
6 | commands.spawn(A);
| ----- ^ invalid `Bundle`
| |
| required by a bound introduced by this call
|
= help: the trait `bevy::prelude::Component` is not implemented for `A`, which is required by `A: Bundle`
= note: consider annotating `A` with `#[derive(Component)]` or `#[derive(Bundle)]`
= help: the following other types implement trait `Bundle`:
TransformBundle
SceneBundle
DynamicSceneBundle
AudioSourceBundle<Source>
SpriteBundle
SpriteSheetBundle
Text2dBundle
MaterialMesh2dBundle<M>
and 34 others
= note: required for `A` to implement `Bundle`
note: required by a bound in `bevy::prelude::Commands::<'w, 's>::spawn`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\commands\mod.rs:243:21
|
243 | pub fn spawn<T: Bundle>(&mut self, bundle: T) -> EntityCommands {
| ^^^^^^ required by this bound in `Commands::<'w, 's>::spawn`
```
</details>
### Missing `#[derive(Asset)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct A;
fn main() {
App::new()
.init_asset::<A>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `A` is not an `Asset`
--> examples/app/empty.rs:7:23
|
7 | .init_asset::<A>()
| ---------- ^ invalid `Asset`
| |
| required by a bound introduced by this call
|
= help: the trait `Asset` is not implemented for `A`
= note: consider annotating `A` with `#[derive(Asset)]`
= help: the following other types implement trait `Asset`:
Font
AnimationGraph
DynamicScene
Scene
AudioSource
Pitch
bevy::bevy_gltf::Gltf
GltfNode
and 17 others
note: required by a bound in `init_asset`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_asset\src\lib.rs:307:22
|
307 | fn init_asset<A: Asset>(&mut self) -> &mut Self;
| ^^^^^ required by this bound in `AssetApp::init_asset`
```
</details>
### Mismatched Input and Output on System Piping
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
fn producer() -> u32 {
123
}
fn consumer(_: In<u16>) {}
fn main() {
App::new()
.add_systems(Update, producer.pipe(consumer))
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `fn(bevy::prelude::In<u16>) {consumer}` is not a valid system with input `u32` and output `_`
--> examples/app/empty.rs:11:44
|
11 | .add_systems(Update, producer.pipe(consumer))
| ---- ^^^^^^^^ invalid system
| |
| required by a bound introduced by this call
|
= help: the trait `bevy::prelude::IntoSystem<u32, _, _>` is not implemented for fn item `fn(bevy::prelude::In<u16>) {consumer}`
= note: expecting a system which consumes `u32` and produces `_`
note: required by a bound in `pipe`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\mod.rs:168:12
|
166 | fn pipe<B, Final, MarkerB>(self, system: B) -> PipeSystem<Self::System, B::System>
| ---- required by a bound in this associated function
167 | where
168 | B: IntoSystem<Out, Final, MarkerB>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IntoSystem::pipe`
```
</details>
### Missing Reflection
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Component)]
struct MyComponent;
fn main() {
App::new()
.register_type::<MyComponent>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `MyComponent` does not provide type registration information
--> examples/app/empty.rs:8:26
|
8 | .register_type::<MyComponent>()
| ------------- ^^^^^^^^^^^ the trait `GetTypeRegistration` is not implemented for `MyComponent`
| |
| required by a bound introduced by this call
|
= note: consider annotating `MyComponent` with `#[derive(Reflect)]`
= help: the following other types implement trait `GetTypeRegistration`:
bool
char
isize
i8
i16
i32
i64
i128
and 443 others
note: required by a bound in `bevy::prelude::App::register_type`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:619:29
|
619 | pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::register_type`
```
</details>
### Missing `#[derive(States)]` Implementation
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash)]
enum AppState {
#[default]
Menu,
InGame {
paused: bool,
turbo: bool,
},
}
fn main() {
App::new()
.init_state::<AppState>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: the trait bound `AppState: FreelyMutableState` is not satisfied
--> examples/app/empty.rs:15:23
|
15 | .init_state::<AppState>()
| ---------- ^^^^^^^^ the trait `FreelyMutableState` is not implemented for `AppState`
| |
| required by a bound introduced by this call
|
= note: consider annotating `AppState` with `#[derive(States)]`
note: required by a bound in `bevy::prelude::App::init_state`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:282:26
|
282 | pub fn init_state<S: FreelyMutableState + FromWorld>(&mut self) -> &mut Self {
| ^^^^^^^^^^^^^^^^^^ required by this bound in `App::init_state`
```
</details>
### Adding a `System` with Unhandled Output
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
fn producer() -> u32 {
123
}
fn main() {
App::new()
.add_systems(Update, consumer)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `fn() -> u32 {producer}` does not describe a valid system configuration
--> examples/app/empty.rs:9:30
|
9 | .add_systems(Update, producer)
| ----------- ^^^^^^^^ invalid system configuration
| |
| required by a bound introduced by this call
|
= help: the trait `IntoSystem<(), (), _>` is not implemented for fn item `fn() -> u32 {producer}`, which is required by `fn() -> u32 {producer}: IntoSystemConfigs<_>`
= help: the following other types implement trait `IntoSystemConfigs<Marker>`:
<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)> as IntoSystemConfigs<()>>
<NodeConfigs<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)>> as IntoSystemConfigs<()>>
<(S0,) as IntoSystemConfigs<(SystemConfigTupleMarker, P0)>>
<(S0, S1) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1)>>
<(S0, S1, S2) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2)>>
<(S0, S1, S2, S3) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3)>>
<(S0, S1, S2, S3, S4) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4)>>
<(S0, S1, S2, S3, S4, S5) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4, P5)>>
and 14 others
= note: required for `fn() -> u32 {producer}` to implement `IntoSystemConfigs<_>`
note: required by a bound in `bevy::prelude::App::add_systems`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:342:23
|
339 | pub fn add_systems<M>(
| ----------- required by a bound in this associated function
...
342 | systems: impl IntoSystemConfigs<M>,
| ^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::add_systems`
```
</details>
</details>
## Testing
CI passed locally.
## Migration Guide
Upgrade to version 1.78 (or higher) of Rust.
## Future Work
- Currently, hints are not supported in this diagnostic. Ideally,
suggestions like _"consider using ..."_ would be in a hint rather than a
note, but that is the best option for now.
- System chaining and other `all_tuples!(...)`-based traits have bad
error messages due to the slightly different error message format.
---------
Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
Provides a `WorldQuery` implementation on `Mut<T>` that forwards to the
implementation on `&mut T`, and give users a way to opt-in to change
detection in auto-generated `QueryData::ReadOnly` types.
Fixes#13329.
## Solution
I implemented `WorldQuery` on `Mut<'w, T>` as a forwarding
implementation to `&mut T`, setting the `QueryData::ReadOnly` associated
type to `Ref<'w, T>`. This provides users the ability to explicitly
opt-in to change detection in the read-only forms of queries.
## Testing
A documentation test was added to `Mut` showcasing the new
functionality.
---
## Changelog
### Added
- Added an implementation of `WorldQuery` and `QueryData` on
`bevy_ecs::change_detection::Mut`.
# Objective
Passing `&World` in the `WorldQuery::get_state` method is unnecessary,
as all implementations of this method in the engine either only access
`Components` in `&World`, or do nothing with it.
It can introduce UB by necessitating the creation of a `&World` from a
`UnsafeWorldCell`.
This currently happens in `Query::transmute_lens`, which obtains a
`&World` from the internal `UnsafeWorldCell` solely to pass to
`get_state`. `Query::join` suffers from the same issue.
Other cases of UB come from allowing implementors of `WorldQuery` to
freely access `&World`, like in the `bevy-trait-query` crate, where a
[reference to a resource is
obtained](0c0e7dd646/src/lib.rs (L445))
inside of
[`get_state`](0c0e7dd646/src/one.rs (L245)),
potentially aliasing with a `ResMut` parameter in the same system.
`WorldQuery::init_state` currently requires `&mut World`, which doesn't
suffer from these issues.
But that too can be changed to receive a wrapper around `&mut
Components` and `&mut Storages` for consistency in a follow-up PR.
## Solution
Replace the `&World` parameter in `get_state` with `&Components`.
## Changelog
`WorldQuery::get_state` now takes `&Components` instead of `&World`.
The `transmute`, `transmute_filtered`, `join` and `join_filtered`
methods on `QueryState` now similarly take `&Components` instead of
`&World`.
## Migration Guide
Users of `WorldQuery::get_state` or `transmute`, `transmute_filtered`,
`join` and `join_filtered` methods on `QueryState` now need to pass
`&Components` instead of `&World`.
`&Components` can be trivially obtained from either `components` method
on `&World` or `UnsafeWorldCell`.
For implementors of `WorldQuery::get_state` that were accessing more
than the `Components` inside `&World` and its methods, this is no longer
allowed.
# Objective
As was pointed out in #13183, `bevy_mikktspace` is missing it's msrv
from it `Cargo.toml`. This promted me to check the msrv of every
`bevy_*` crate. Closes#13183.
## Solution
- Call `cargo check` with different rust versions on every bevy crate
until it doesn't complain.
- Write down the rust version `cargo check` started working.
## Testing
- Install `cargo-msrv`.
- Run `cargo msrv verify`.
- Rejoice.
---
## Changelog
Every published bevy crate now specifies a MSRV. If your rust toolchain
isn't at least version `1.77.0` You'll likely not be able to compile
most of bevy.
## Migration Guide
If your rust toolchain is bellow version`1.77.0, update.
# Objective
Extracts the state mechanisms into a new crate called "bevy_state".
This comes with a few goals:
- state wasn't really an inherent machinery of the ecs system, and so
keeping it within bevy_ecs felt forced
- by mixing it in with bevy_ecs, the maintainability of our more robust
state system was significantly compromised
moving state into a new crate makes it easier to encapsulate as it's own
feature, and easier to read and understand since it's no longer a
single, massive file.
## Solution
move the state-related elements from bevy_ecs to a new crate
## Testing
- Did you test these changes? If so, how? all the automated tests
migrated and passed, ran the pre-existing examples without changes to
validate.
---
## Migration Guide
Since bevy_state is now gated behind the `bevy_state` feature, projects
that use state but don't use the `default-features` will need to add
that feature flag.
Since it is no longer part of bevy_ecs, projects that use bevy_ecs
directly will need to manually pull in `bevy_state`, trigger the
StateTransition schedule, and handle any of the elements that bevy_app
currently sets up.
---------
Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
# Objective
fixes#13224
adds conversions for Vec3 and Vec4 since these appear so often
## Solution
added Covert trait (couldn't think of good name) for [f32; 4], [f32, 3],
Vec4, and Vec3 along with the symmetric implementation
## Changelog
added conversions between arrays and vector to colors and vice versa
#migration
LinearRgba appears to have already had implicit conversions for [f32;4]
and Vec4
# Objective
Fixes#12966
## Solution
Renaming multi_threaded feature to match snake case
## Migration Guide
Bevy feature multi-threaded should be refered to multi_threaded from now
on.
# Objective
- Follow-up of #13184 :)
- We use `ui_test` to test compiler errors for our custom macros.
- There are four crates related to compile fail tests
- `bevy_ecs_compile_fail_tests`, `bevy_macros_compile_fail_tests`, and
`bevy_reflect_compile_fail_tests`, which actually test the macros.
-
[`bevy_compile_test_utils`](64c1c65783/crates/bevy_compile_test_utils),
which provides helpers and common patterns for these tests.
- All of these crates reside within the `crates` directory.
- This can be confusing, especially for newcomers. All of the other
folders in `crates` are actual published libraries, except for these 4.
## Solution
- Move all compile fail tests to a `compile_fail` folder under their
corresponding crate.
- E.g. `crates/bevy_ecs_compile_fail_tests` would be moved to
`crates/bevy_ecs/compile_fail`.
- Move `bevy_compile_test_utils` to `tools/compile_fail_utils`.
There are a few benefits to this approach:
1. An internal testing detail is less intrusive (and confusing) for
those who just want to browse the public Bevy interface.
2. Follows a pre-existing approach of organizing related crates inside a
larger crate's folder.
- See `bevy_gizmos/macros` for an example.
4. Makes consistent the terms `compile_test`, `compile_fail`, and
`compile_fail_test` in code. It's all just `compile_fail` now, because
we are specifically testing the error messages on compiler failures.
- To be clear it can still be referred to by these terms in comments and
speech, just the names of the crates and the CI command are now
consistent.
## Testing
Run the compile fail CI command:
```shell
cargo run -p ci -- compile-fail
```
If it still passes, then my refactor was successful.
# Objective
Resolves#13185
## Solution
Move the following methods from `sub_app` to the `Schedules` resource,
and use them in the sub app:
- `add_systems`
- `configure_sets`
- `ignore_ambiguity`
Add an `entry(&mut self, label: impl ScheduleLabel) -> &mut Schedule`
method to the `Schedules` resource, which returns a mutable reference to
the schedule associated with the label, and creates one if it doesn't
already exist. (build on top of the `entry(..).or_insert_with(...)`
pattern in `HashMap`.
## Testing
- Did you test these changes? If so, how? Added 4 unit tests to the
`schedule.rs` - one that validates adding a system to an existing
schedule, one that validates adding a system to a new one, one that
validates configuring sets on an existing schedule, and one that
validates configuring sets on a new schedule.
- I didn't add tests for `entry` since the previous 4 tests use
functions that rely on it.
- I didn't test `ignore_ambiguity` since I didn't see examples of it's
use, and am not familiar enough with it to know how to set up a good
test for it. However, it relies on the `entry` method as well, so it
should work just like the other 2 methods.
## Summary/Description
This PR extends states to allow support for a wider variety of state
types and patterns, by providing 3 distinct types of state:
- Standard [`States`] can only be changed by manually setting the
[`NextState<S>`] resource. These states are the baseline on which the
other state types are built, and can be used on their own for many
simple patterns. See the [state
example](https://github.com/bevyengine/bevy/blob/latest/examples/ecs/state.rs)
for a simple use case - these are the states that existed so far in
Bevy.
- [`SubStates`] are children of other states - they can be changed
manually using [`NextState<S>`], but are removed from the [`World`] if
the source states aren't in the right state. See the [sub_states
example](https://github.com/lee-orr/bevy/blob/derived_state/examples/ecs/sub_states.rs)
for a simple use case based on the derive macro, or read the trait docs
for more complex scenarios.
- [`ComputedStates`] are fully derived from other states - they provide
a [`compute`](ComputedStates::compute) method that takes in the source
states and returns their derived value. They are particularly useful for
situations where a simplified view of the source states is necessary -
such as having an `InAMenu` computed state derived from a source state
that defines multiple distinct menus. See the [computed state
example](https://github.com/lee-orr/bevy/blob/derived_state/examples/ecs/computed_states.rscomputed_states.rs)
to see a sampling of uses for these states.
# Objective
This PR is another attempt at allowing Bevy to better handle complex
state objects in a manner that doesn't rely on strict equality. While my
previous attempts (https://github.com/bevyengine/bevy/pull/10088 and
https://github.com/bevyengine/bevy/pull/9957) relied on complex matching
capacities at the point of adding a system to application, this one
instead relies on deterministically deriving simple states from more
complex ones.
As a result, it does not require any special macros, nor does it change
any other interactions with the state system once you define and add
your derived state. It also maintains a degree of distinction between
`State` and just normal application state - your derivations have to end
up being discreet pre-determined values, meaning there is less of a
risk/temptation to place a significant amount of logic and data within a
given state.
### Addition - Sub States
closes#9942
After some conversation with Maintainers & SMEs, a significant concern
was that people might attempt to use this feature as if it were
sub-states, and find themselves unable to use it appropriately. Since
`ComputedState` is mainly a state matching feature, while `SubStates`
are more of a state mutation related feature - but one that is easy to
add with the help of the machinery introduced by `ComputedState`, it was
added here as well. The relevant discussion is here:
https://discord.com/channels/691052431525675048/1200556329803186316
## Solution
closes#11358
The solution is to create a new type of state - one implementing
`ComputedStates` - which is deterministically tied to one or more other
states. Implementors write a function to transform the source states
into the computed state, and it gets triggered whenever one of the
source states changes.
In addition, we added the `FreelyMutableState` trait , which is
implemented as part of the derive macro for `States`. This allows us to
limit use of `NextState<S>` to states that are actually mutable,
preventing mis-use of `ComputedStates`.
---
## Changelog
- Added `ComputedStates` trait
- Added `FreelyMutableState` trait
- Converted `NextState` resource to an Enum, with `Unchanged` and
`Pending`
- Added `App::add_computed_state::<S: ComputedStates>()`, to allow for
easily adding derived states to an App.
- Moved the `StateTransition` schedule label from `bevy_app` to
`bevy_ecs` - but maintained the export in `bevy_app` for continuity.
- Modified the process for updating states. Instead of just having an
`apply_state_transition` system that can be added anywhere, we now have
a multi-stage process that has to run within the `StateTransition`
label. First, all the state changes are calculated - manual transitions
rely on `apply_state_transition`, while computed transitions run their
computation process before both call `internal_apply_state_transition`
to apply the transition, send out the transition event, trigger
dependent states, and record which exit/transition/enter schedules need
to occur. Once all the states have been updated, the transition
schedules are called - first the exit schedules, then transition
schedules and finally enter schedules.
- Added `SubStates` trait
- Adjusted `apply_state_transition` to be a no-op if the `State<S>`
resource doesn't exist
## Migration Guide
If the user accessed the NextState resource's value directly or created
them from scratch they will need to adjust to use the new enum variants:
- if they created a `NextState(Some(S))` - they should now use
`NextState::Pending(S)`
- if they created a `NextState(None)` -they should now use
`NextState::Unchanged`
- if they matched on the `NextState` value, they would need to make the
adjustments above
If the user manually utilized `apply_state_transition`, they should
instead use systems that trigger the `StateTransition` schedule.
---
## Future Work
There is still some future potential work in the area, but I wanted to
keep these potential features and changes separate to keep the scope
here contained, and keep the core of it easy to understand and use.
However, I do want to note some of these things, both as inspiration to
others and an illustration of what this PR could unlock.
- `NextState::Remove` - Now that the `State` related mechanisms all
utilize options (#11417), it's fairly easy to add support for explicit
state removal. And while `ComputedStates` can add and remove themselves,
right now `FreelyMutableState`s can't be removed from within the state
system. While it existed originally in this PR, it is a different
question with a separate scope and usability concerns - so having it as
it's own future PR seems like the best approach. This feature currently
lives in a separate branch in my fork, and the differences between it
and this PR can be seen here: https://github.com/lee-orr/bevy/pull/5
- `NextState::ReEnter` - this would allow you to trigger exit & entry
systems for the current state type. We can potentially also add a
`NextState::ReEnterRecirsive` to also re-trigger any states that depend
on the current one.
- More mechanisms for `State` updates - This PR would finally make
states that aren't a set of exclusive Enums useful, and with that comes
the question of setting state more effectively. Right now, to update a
state you either need to fully create the new state, or include the
`Res<Option<State<S>>>` resource in your system, clone the state, mutate
it, and then use `NextState.set(my_mutated_state)` to make it the
pending next state. There are a few other potential methods that could
be implemented in future PRs:
- Inverse Compute States - these would essentially be compute states
that have an additional (manually defined) function that can be used to
nudge the source states so that they result in the computed states
having a given value. For example, you could use set the `IsPaused`
state, and it would attempt to pause or unpause the game by modifying
the `AppState` as needed.
- Closure-based state modification - this would involve adding a
`NextState.modify(f: impl Fn(Option<S> -> Option<S>)` method, and then
you can pass in closures or function pointers to adjust the state as
needed.
- Message-based state modification - this would involve either creating
states that can respond to specific messages, similar to Elm or Redux.
These could either use the `NextState` mechanism or the Event mechanism.
- ~`SubStates` - which are essentially a hybrid of computed and manual
states. In the simplest (and most likely) version, they would work by
having a computed element that determines whether the state should
exist, and if it should has the capacity to add a new version in, but
then any changes to it's content would be freely mutated.~ this feature
is now part of this PR. See above.
- Lastly, since states are getting more complex there might be value in
moving them out of `bevy_ecs` and into their own crate, or at least out
of the `schedule` module into a `states` module. #11087
As mentioned, all these future work elements are TBD and are explicitly
not part of this PR - I just wanted to provide them as potential
explorations for the future.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Marcel Champagne <voiceofmarcel@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
# Objective
I'm reading through the schedule code, which is somewhat lacking
documentation.
I've been adding some docstrings to help me understand the code; I feel
like some of them could be useful to also help others read this code.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
The `Events` containerr should be reflectable, in order to make dev
tools that examine its state more useful.
Fixes#13148.
## Solution
- Add a `Reflect` derive to `Events`, gated behind the `bevy_reflect`
feature
- Add `Reflect` to the contained types to make everything compile.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
# Objective
- `from_reflect_or_world` is an internal utilty used in the
implementations of `ReflectComponent` and `ReflectBundle` to create a
`T` given a `&dyn Reflect` by trying to use `FromReflect`, and if that
fails it falls back to `ReflectFromWorld`
- reflecting `FromWorld` is not intuitive though: often it is implicitly
implemented by deriving `Default` so people might not even be aware of
it.
- the panic messages mentioning `ReflectFromWorld` are not directly
correlated to what the user would have to do (reflect `FromWorld`)
## Solution
- Also check for `ReflectDefault` in addition to `ReflectFromWorld`.
- Change the panic messages to mention the reflected trait rather than
the `Reflect*` types.
---
## Changelog
- `ReflectComponent` and `ReflectBundle` no longer require `T:
FromReflect` but instead only `T: Reflect`.
- `ReflectComponent` and `ReflectBundle` will also work with types that
only reflected `Default` and not `FromWorld`.
## Migration Guide
- `ReflectBundle::insert` now requires an additional `&TypeRegistry`
parameter.
# Objective
- Better `SystemId` <-> `Entity` conversion.
## Solution
- Provide a method `SystemId::from_entity` to create a `SystemId<I, O>`
form an `Entity`. When users want to deal with the entities manually
they need a way to convert the `Entity` back to a `SystemId` to actually
run the system with `Commands` or `World`.
- Provide a method `SystemId::entity` that returns an `Entity` from
`SystemId`. The current `From` impl is not very discoverable as it does
not appear on the `SystemId` doc page.
- Remove old `From` impl.
## Migration Guide
```rust
let system_id = world.register_system(my_sys);
// old
let entity = Entity::from(system_id);
// new
let entity = system_id.entity();
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Closes#12958
## Solution
- Find all methods under `Query` that mention panicking, and add
`#[track_caller]` to them.
---
## Changelog
- Added `#[track_caller]` to `Query::many`, `Query::many_mut`,
`Query::transmute_lens`, and `Query::transmute_lens_filtered`.
## For reviewers
I'm unfamiliar with the depths of the `Query` struct. Please check
whether it makes since for the updated methods to have
`#[track_caller]`, and if I missed any!
# Objective
- Clippy raises a few warnings on the latest nightly release. 📎
## Solution
- Use `ptr::from_ref` when possible, because it prevents you from
accidentally changing the mutability as well as its type.
- Use `ptr::addr_eq` when comparing two pointers, ignoring pointer
metadata.
# Objective
- bevy usually use `Parallel::scope` to collect items from `par_iter`,
but `scope` will be called with every satifified items. it will cause a
lot of unnecessary lookup.
## Solution
- similar to Rayon ,we introduce `for_each_init` for `par_iter` which
only be invoked when spawn a task for a group of items.
---
## Changelog
- added `for_each_init`
## Performance
`check_visibility ` in `many_foxes `
~40% performance gain in `check_visibility`.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Allow parallel iteration over events, resolve#10766
## Solution
- Add `EventParIter` which works similarly to `QueryParIter`,
implementing a `for_each{_with_id}` operator.
I chose to not mirror `EventIteratorWithId` and instead implement both
operations on a single struct.
- Reuse `BatchingStrategy` from `QueryParIter`
## Changelog
- `EventReader` now supports parallel event iteration using
`par_read().for_each(|event| ...)`.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
# Objective
Fix#2128. Both `Query::new_archetype` and `SystemParam::new_archetype`
do not check if the `Archetype` comes from the same World the state is
initialized from. This could result in unsoundness via invalid accesses
if called incorrectly.
## Solution
Make them `unsafe` functions and lift the invariant to the caller. This
also caught one instance of us not validating the World in
`SystemState::update_archetypes_unsafe_world_cell`'s implementation.
---
## Changelog
Changed: `QueryState::new_archetype` is now an unsafe function.
Changed: `SystemParam::new_archetype` is now an unsafe function.
## Migration Guide
`QueryState::new_archetype` and `SystemParam::new_archetype` are now an
unsafe functions that must be sure that the provided `Archetype` is from
the same `World` that the state was initialized from. Callers may need
to add additional assertions or propagate the safety invariant upwards
through the callstack to ensure safety.
# Objective
- Fixes#13024.
## Solution
- Run `cargo clippy --target wasm32-unknown-unknown` until there are no
more errors.
- I recommend reviewing one commit at a time :)
---
## Changelog
- Fixed Clippy lints for `wasm32-unknown-unknown` target.
- Updated `bevy_transform`'s `README.md`.
# Objective
- Fixes#12976
## Solution
This one is a doozy.
- Run `cargo +beta clippy --workspace --all-targets --all-features` and
fix all issues
- This includes:
- Moving inner attributes to be outer attributes, when the item in
question has both inner and outer attributes
- Use `ptr::from_ref` in more scenarios
- Extend the valid idents list used by `clippy:doc_markdown` with more
names
- Use `Clone::clone_from` when possible
- Remove redundant `ron` import
- Add backticks to **so many** identifiers and items
- I'm sorry whoever has to review this
---
## Changelog
- Added links to more identifiers in documentation.
# Objective
Improve the code quality of the multithreaded executor.
## Solution
* Remove some unused variables.
* Use `Mutex::get_mut` where applicable instead of locking.
* Use a `startup_systems` FixedBitset to pre-compute the starting
systems instead of building it bit-by-bit on startup.
* Instead of using `FixedBitset::clear` and `FixedBitset::union_with`,
use `FixedBitset::clone_from` instead, which does only a single copy and
will not allocate if the target bitset has a large enough allocation.
* Replace the `Mutex` around `Conditions` with `SyncUnsafeCell`, and add
a `Context::try_lock` that forces it to be synchronized fetched
alongside the executor lock.
This might produce minimal performance gains, but the focus here is on
the code quality improvements.
# Objective
- ~~This PR adds more flexible versions of `set_if_neq` and
`replace_if_neq` to only compare and update certain fields of a
components which is not just a newtype~~
- https://github.com/bevyengine/bevy/pull/12919#issuecomment-2048049786
gave a good solution to the original problem, so let's update the docs
so that this is easier to find
## Solution
- ~~Add `set_if_neq_with` and `replace_if_neq_with` which take an
accessor closure to access the relevant field~~
---
In a recent project, a scenario emerged that required careful
consideration regarding change detection without compromising
performance. The context involves a component that maintains a
collection of `Vec<Vec2>` representing a horizontal surface, alongside a
height field. When the height is updated, there are a few approaches to
consider:
1. Clone the collection of points to utilize the existing `set_if_neq`
method.
2. Inline and adjust the `set_if_neq` code specifically for this
scenario.
3. (Consider splitting the component into more granular components.)
It's worth noting that the third option might be the most suitable in
most cases.
A similar situation arises with the Bevy internal Transform component,
which includes fields for translation, rotation, and scale. These fields
are relatively small (`Vec3` or `Quat` with 3 or 4 `f32` values), but
the creation of a single pointer (`usize`) might be more efficient than
copying the data of the other fields. This is speculative, and insights
from others could be valuable.
Questions remain:
- Is it feasible to develop a more flexible API, and what might that
entail?
- Is there general interest in this change?
There's no hard feelings if this idea or the PR is ultimately rejected.
I just wanted to put this idea out there and hope that this might be
beneficial to others and that feedback could be valuable before
abandoning the idea.
# Objective
The system task span is pretty consistent in how much time it uses, so
all it adds is overhead/additional bandwidth when profiling.
## Solution
Remove it.
# Objective
Improve performance scalability when adding new event types to a Bevy
app. Currently, just using Bevy in the default configuration, all apps
spend upwards of 100+us in the `First` schedule, every app tick,
evaluating if it should update events or not, even if events are not
being used for that particular frame, and this scales with the number of
Events registered in the app.
## Solution
As `Events::update` is guaranteed `O(1)` by just checking if a
resource's value, swapping two Vecs, and then clearing one of them, the
actual cost of running `event_update_system` is *very* cheap. The
overhead of doing system dependency injection, task scheduling ,and the
multithreaded executor outweighs the cost of running the system by a
large margin.
Create an `EventRegistry` resource that keeps a number of function
pointers that update each event. Replace the per-event type
`event_update_system` with a singular exclusive system uses the
`EventRegistry` to update all events instead. Update `SubApp::add_event`
to use `EventRegistry` instead.
## Performance
This speeds reduces the cost of the `First` schedule in both many_foxes
and many_cubes by over 80%. Note this is with system spans on. The
majority of this is now context-switching costs from launching
`time_system`, which should be mostly eliminated with #12869.
The actual `event_update_system` is usually *very* short, using only a
few microseconds on average.
---
## Changelog
TODO
## Migration Guide
TODO
---------
Co-authored-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I daily drive nightly Rust when developing Bevy, so I notice when new
warnings are raised by `cargo check` and Clippy.
- `cargo +nightly clippy` raises a few of these new warnings.
## Solution
- Fix most warnings from `cargo +nightly clippy`
- I skipped the docs-related warnings because some were covered by
#12692.
- Use `Clone::clone_from` in applicable scenarios, which can sometimes
avoid an extra allocation.
- Implement `Default` for structs that have a `pub const fn new() ->
Self` method.
- Fix an occurrence where generic constraints were defined in both `<C:
Trait>` and `where C: Trait`.
- Removed generic constraints that were implied by the `Bundle` trait.
---
## Changelog
- `BatchingStrategy`, `NonGenericTypeCell`, and `GenericTypeCell` now
implement `Default`.
# Objective
Minimize the number of dependencies low in the tree.
## Solution
* Remove the dependency on rustc-hash in bevy_ecs (not used) and
bevy_macro_utils (only used in one spot).
* Deduplicate the dependency on `sha1_smol` with the existing blake3
dependency already being used for bevy_asset.
* Remove the unused `ron` dependency on `bevy_app`
* Make the `serde` dependency for `bevy_ecs` optional. It's only used
for serializing Entity.
* Change the `wgpu` dependency to `wgpu-types`, and make it optional for
`bevy_color`.
* Remove the unused `thread-local` dependency on `bevy_render`.
* Make multiple dependencies for `bevy_tasks` optional and enabled only
when running with the `multi-threaded` feature. Preferably they'd be
disabled all the time on wasm, but I couldn't find a clean way to do
this.
---
## Changelog
TODO
## Migration Guide
TODO
# Objective
- Attempts to solve two items from
https://github.com/bevyengine/bevy/issues/11478.
## Solution
- Moved `intern` module from `bevy_utils` into `bevy_ecs` crate and
updated all relevant imports.
- Moved `label` module from `bevy_utils` into `bevy_ecs` crate and
updated all relevant imports.
---
## Migration Guide
- Replace `bevy_utils::define_label` imports with
`bevy_ecs::define_label` imports.
- Replace `bevy_utils:🏷️:DynEq` imports with
`bevy_ecs:🏷️:DynEq` imports.
- Replace `bevy_utils:🏷️:DynHash` imports with
`bevy_ecs:🏷️:DynHash` imports.
- Replace `bevy_utils::intern::Interned` imports with
`bevy_ecs::intern::Interned` imports.
- Replace `bevy_utils::intern::Internable` imports with
`bevy_ecs::intern::Internable` imports.
- Replace `bevy_utils::intern::Interner` imports with
`bevy_ecs::intern::Interner` imports.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Make `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` work with `EntityMut` too (currently they only
work with the more restricting `EntityWorldMut`);
- Note: support for the `Filtered*` variants has been left out since the
conversion in that case is more expensive. Let me know if I should add
support for them too.
## Solution
- Make `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` take an `impl Into<EntityMut<'a>>`;
- Make the corresponding `*Fns` function pointers take a `EntityMut`.
---
## Changelog
- `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` now accept `EntityMut` as well
## Migration Guide
- `ReflectComponentFns`'s `apply` and `reflect_mut` fields now take
`EntityMut` instead of `&mut EntityWorldMut`
- `ReflectBundleFns`'s `apply` field now takes `EntityMut` instead of
`&mut EntityWorldMut`
# Objective
- Implement `From<&'w mut EntityMut>` for `EntityMut<'w>`;
- Make it possible to pass `&mut EntityMut` where `impl Into<EntityMut>`
is required;
- Helps with #12895.
## Solution
- Implement `From<&'w mut EntityMut>` for `EntityMut<'w>`
---
## Changelog
- `EntityMut<'w>` now implements `From<&'w mut EntityMut>`
# Objective
- Fix#7303
- bevy would spawn a lot of tasks in parallel iteration when it matchs a
large storage and many small storage ,it significantly increase the
overhead of schedule.
## Solution
- collect small storage into one task
# Objective
Fix#11931
## Solution
- Make stepping a non-default feature
- Adjust documentation and examples
- In particular, make the breakout example not show the stepping prompt
if compiled without the feature (shows a log message instead)
---
## Changelog
- Removed `bevy_debug_stepping` from default features
## Migration Guide
The system-by-system stepping feature is now disabled by default; to use
it, enable the `bevy_debug_stepping` feature explicitly:
```toml
[dependencies]
bevy = { version = "0.14", features = ["bevy_debug_stepping"] }
```
Code using
[`Stepping`](https://docs.rs/bevy/latest/bevy/ecs/schedule/struct.Stepping.html)
will still compile with the feature disabled, but will print a runtime
error message to the console if the application attempts to enable
stepping.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Add `remove_by_id` method to `EntityWorldMut` and `EntityCommands`
- This is a duplicate of the awesome work by @mateuseap, last updated
04/09/23 - #9663
- I'm opening a second one to ensure the feature makes it into `0.14`
- Fixes#9261
## Solution
Almost identical to #9663 with three exceptions
- Uses a closure instead of struct for commands, consistent with other
similar commands
- Does not refactor `EntityCommands::insert`, so no migration guide
- `EntityWorldMut::remove_by_id` is now safe containing unsafe blocks, I
think thats what @SkiFire13 was indicating should happen [in this
comment](https://github.com/bevyengine/bevy/pull/9663#discussion_r1314307525)
## Changelog
- Added `EntityWorldMut::remove_by_id` method and its tests.
- Added `EntityCommands::remove_by_id` method and its tests.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Closes#12019
- Related to #4955
- Useful for dev_tools and networking
## Solution
- Create `World::iter_resources()` and `World::iter_resources_mut()`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
# Objective
- Since #10811,Bevy uses `assert `in the hot path of iteration. The
`for_each `method has an assert in the outer loop to help the compiler
remove unnecessary branching in the internal loop.
- However , ` for` style iterations do not receive the same treatment.
it still have a branch check in the internal loop, which could
potentially hurt performance.
## Solution
- use `TableRow::from_u32 ` instead of ` TableRow::from_usize` to avoid
unnecessary branch.
Before
After
----------------------------------------------------------------------------
# Objective
Sometimes it's useful to iterate over removed entities. For example, in
my library
[bevy_replicon](https://github.com/projectharmonia/bevy_replicon) I need
it to iterate over all removals to replicate them over the network.
Right now we do lookups, but it would be more convenient and faster to
just iterate over all removals.
## Solution
Add `RemovedComponentEvents::iter`.
---
## Changelog
### Added
- `RemovedComponentEvents::iter` to iterate over all removed components.
---------
Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
# Objective
- There are several redundant imports in the tests and examples that are
not caught by CI because additional flags need to be passed.
## Solution
- Run `cargo check --workspace --tests` and `cargo check --workspace
--examples`, then fix all warnings.
- Add `test-check` to CI, which will be run in the check-compiles job.
This should catch future warnings for tests. Examples are already
checked, but I'm not yet sure why they weren't caught.
## Discussion
- Should the `--tests` and `--examples` flags be added to CI, so this is
caught in the future?
- If so, #12818 will need to be merged first. It was also a warning
raised by checking the examples, but I chose to split off into a
separate PR.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- The `bundles` parameter in `insert_or_spawn_batch` method has
inconsistent naming with docs (e.g. `bundles_iter`) since #11107.
## Solution
- Replace `bundles` with `bundles_iter`, as `bundles_iter` is more
expressive to its type.
# Objective
Other than the exposed functions for reading matched tables and
archetypes, a `QueryState` does not actually need both internal Vecs for
storing matched archetypes and tables. In practice, it will only use one
of the two depending on if it uses dense or archetypal iteration.
Same vein as #12474. The goal is to reduce the memory overhead of using
queries, which Bevy itself, ecosystem plugins, and end users are already
fairly liberally using.
## Solution
Add `StorageId`, which is a union over `TableId` and `ArchetypeId`, and
store only one of the two at runtime. Read the slice as if it was one ID
depending on whether the query is dense or not.
This follows in the same vein as #5085; however, this one directly
impacts heap memory usage at runtime, while #5085 primarily targeted
transient pointers that might not actually exist at runtime.
---
## Changelog
Changed: `QueryState::matched_tables` now returns an iterator instead of
a reference to a slice.
Changed: `QueryState::matched_archetypes` now returns an iterator
instead of a reference to a slice.
## Migration Guide
`QueryState::matched_tables` and `QueryState::matched_archetypes` does
not return a reference to a slice, but an iterator instead. You may need
to use iterator combinators or collect them into a Vec to use it as a
slice.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#12752. Fixes#12750. Document the runtime complexity of all of
the `O(1)` operations on the individual APIs.
## Solution
* Mirror `Query::contains` onto `QueryState::contains`
* Make `QueryState::as_nop` pub(crate)
* Make `NopWorldQuery` pub(crate)
* Document all of the O(1) operations on Query and QueryState.
# Objective
Fixes#12392, fixes#12393, and fixes#11387. Implement QueryData for
Archetype and EntityLocation.
## Solution
Add impls for both of the types.
---
## Changelog
Added: `&Archetype` now implements `QueryData`
Added: `EntityLocation` now implements `QueryData`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Resolves#3824. `unsafe` code should be the exception, not the norm in
Rust. It's obviously needed for various use cases as it's interfacing
with platforms and essentially running the borrow checker at runtime in
the ECS, but the touted benefits of Bevy is that we are able to heavily
leverage Rust's safety, and we should be holding ourselves accountable
to that by minimizing our unsafe footprint.
## Solution
Deny `unsafe_code` workspace wide. Add explicit exceptions for the
following crates, and forbid it in almost all of the others.
* bevy_ecs - Obvious given how much unsafe is needed to achieve
performant results
* bevy_ptr - Works with raw pointers, even more low level than bevy_ecs.
* bevy_render - due to needing to integrate with wgpu
* bevy_window - due to needing to integrate with raw_window_handle
* bevy_utils - Several unsafe utilities used by bevy_ecs. Ideally moved
into bevy_ecs instead of made publicly usable.
* bevy_reflect - Required for the unsafe type casting it's doing.
* bevy_transform - for the parallel transform propagation
* bevy_gizmos - For the SystemParam impls it has.
* bevy_assets - To support reflection. Might not be required, not 100%
sure yet.
* bevy_mikktspace - due to being a conversion from a C library. Pending
safe rewrite.
* bevy_dynamic_plugin - Inherently unsafe due to the dynamic loading
nature.
Several uses of unsafe were rewritten, as they did not need to be using
them:
* bevy_text - a case of `Option::unchecked` could be rewritten as a
normal for loop and match instead of an iterator.
* bevy_color - the Pod/Zeroable implementations were replaceable with
bytemuck's derive macros.
# Objective
Currently the built docs only shows the logo and favicon for the top
level `bevy` crate. This makes views like
https://docs.rs/bevy_ecs/latest/bevy_ecs/ look potentially unrelated to
the project at first glance.
## Solution
Reproduce the docs attributes for every crate that Bevy publishes.
Ideally this would be done with some workspace level Cargo.toml control,
but AFAICT, such support does not exist.
# Objective
Make it easy to get the ids of all the components in a bundle (and
initialise any components not yet initialised). This is fairly similar
to the `Bundle::get_component_ids()` method added in the observers PR
however that will return none for any non-initialised components. This
is exactly the API space covered by `Bundle::component_ids()` however
that isn't possible to call outside of `bevy_ecs` as it requires `&mut
Components` and `&mut Storages`.
## Solution
Added `World.init_bundle<B: Bundle>()` which similarly to
`init_component` and `init_resource`, initialises all components in the
bundle and returns a vector of their component ids.
---
## Changelog
Added the method `init_bundle` to `World` as a counterpart to
`init_component` and `init_resource`.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Tiny PR to clarify that `self.world.bundles.init_info::<T>` must have
been called so that the BundleInfo is present in the World
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
I was reading some of the Archetype and Bundle code and was getting
confused a little bit in some places (is the `archetype_id` in
`AddBundle` the source or the target archetype id?).
Small PR that adds some docstrings to make it easier for first-time
readers.
# Objective
- Allow registering of systems from Commands with
`Commands::register_one_shot_system`
- Make registering of one shot systems more easy
## Solution
- Add the Command `RegisterSystem` for Commands use.
- Creation of SystemId based on lazy insertion of the System
- Changed the privacy of the fields in SystemId so Commands can return
the SystemId
---
## Changelog
### Added
- Added command `RegisterSystem`
- Added function `Commands::register_one_shot_system`
- Added function `App::register_one_shot_system`
### Changed
- Changed the privacy and the type of struct tuple to regular struct of
SystemId
## Migration Guide
- Changed SystemId fields from tuple struct to a normal struct
If you want to access the entity field, you should use
`SystemId::entity` instead of `SystemId::0`
## Showcase
> Before, if you wanted to register a system with `Commands`, you would
need to do:
```rust
commands.add(|world: &mut World| {
let id = world.register_system(your_system);
// You would need to insert the SystemId inside an entity or similar
})
```
> Now, you can:
```rust
let id = commands.register_one_shot_system(your_system);
// Do what you want with the Id
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Pablo Reinhardt <pabloreinhardt@gmail.com>
# Objective
I'm reading through the ecs query code for the first time, and updating
the docs:
- fixed some typos
- added some docs about things I was confused about (in particular what
the difference between `matches_component_set` and
`update_component_access` was)
# Objective
Fix Pr CI failing over dead code in tests and main branch CI failing
over a missing semicolon. Fixes#12620.
## Solution
Add dead_code annotations and a semicolon.
# Objective
Fixes#12549. WorldCell's support of everything a World can do is
incomplete, and represents an alternative, potentially confusing, and
less performant way of pulling multiple fetches from a `World`. The
typical approach is to use `SystemState` for a runtime cached and safe
way, or `UnsafeWorldCell` if the use of `unsafe` is tolerable.
## Solution
Remove it!
---
## Changelog
Removed: `WorldCell`
Removed: `World::cell`
## Migration Guide
`WorldCell` has been removed. If you were using it to fetch multiple
distinct values from a `&mut World`, use `SystemState` by calling
`SystemState::get` instead. Alternatively, if `SystemState` cannot be
used, `UnsafeWorldCell` can instead be used in unsafe contexts.
# Objective
Provide component access to `&'w T`, `Ref<'w, T>`, `Mut<'w, T>`,
`Ptr<'w>` and `MutUntyped<'w>` from `EntityMut<'w>`/`EntityWorldMut<'w>`
with the world `'w` lifetime instead of `'_`.
Fixes#12417
## Solution
Add `into_` prefixed methods for `EntityMut<'w>`/`EntityWorldMut<'w>`
that consume `self` and returns component access with the world `'w`
lifetime unlike the `get_` prefixed methods that takes `&'a self` and
returns component access with `'a` lifetime.
Methods implemented:
- EntityMut::into_borrow
- EntityMut::into_ref
- EntityMut::into_mut
- EntityMut::into_borrow_by_id
- EntityMut::into_mut_by_id
- EntityWorldMut::into_borrow
- EntityWorldMut::into_ref
- EntityWorldMut::into_mut
- EntityWorldMut::into_borrow_by_id
- EntityWorldMut::into_mut_by_id
# Objective
`QueryState::archetype_component_access` is only really ever used to
extend `SystemMeta`'s. It can be removed to save some memory for every
`Query` in an app.
## Solution
* Remove it.
* Have `new_archetype` pass in a `&mut Access<ArchetypeComponentId>`
instead and pull it from `SystemMeta` directly.
* Split `QueryState::new` from `QueryState::new_with_access` and a
common `QueryState::new_uninitialized`.
* Split `new_archetype` into an internal and public version. Call the
internal version in `update_archetypes`.
This should make it faster to construct new QueryStates, and by proxy
lenses and joins as well.
`matched_tables` also similarly is only used to deduplicate inserting
into `matched_table_ids`. If we can find another efficient way to do so,
it might also be worth removing.
The [generated
assembly](https://github.com/james7132/bevy_asm_tests/compare/main...remove-query-state-archetype-component-access#diff-496530101f0b16e495b7e9b77c0e906ae3068c8adb69ed36c92d5a1be5a9efbe)
reflects this well, with all of the access related updates in
`QueryState` being removed.
---
## Changelog
Removed: `QueryState::archetype_component_access`.
Changed: `QueryState::new_archetype` now takes a `&mut
Access<ArchetypeComponentId>` argument, which will be updated with the
new accesses.
Changed: `QueryState::update_archetype_component_access` now takes a
`&mut Access<ArchetypeComponentId>` argument, which will be updated with
the new accesses.
## Migration Guide
TODO
# Objective
Improve code quality involving fixedbitset.
## Solution
Update to fixedbitset 0.5. Use the new `grow_and_insert` function
instead of `grow` and `insert` functions separately.
This should also speed up most of the set operations involving
fixedbitset. They should be ~2x faster, but testing this against the
stress tests seems to show little to no difference. The multithreaded
executor doesn't seem to be all that much faster in many_cubes and
many_foxes. These use cases are likely dominated by other operations or
the bitsets aren't big enough to make them the bottleneck.
This introduces a duplicate dependency due to petgraph and wgpu, but the
former may take some time to update.
## Changelog
Removed: `Access::grow`
## Migration Guide
`Access::grow` has been removed. It's no longer needed. Remove all
references to it.
# Objective
Fixes#12139
## Solution
- Derive `Debug` impl for `Entity`
- Add impl `Display` for `Entity`
- Add `entity_display` test to check the output contains all required
info
I decided to go with `0v0|1234` format as opposed to the `0v0[1234]`
which was initially discussed in the issue.
My rationale for this is that `[1234]` may be confused for index values,
which may be common in logs, and so searching for entities by text would
become harder. I figured `|1234` would help the entity IDs stand out
more.
Additionally, I'm a little concerned that this change is gonna break
existing logging for projects because `Debug` is now going to be a
multi-line output. But maybe this is ok.
We could implement `Debug` to be a single-line output, but then I don't
see why it would be different from `Display` at all.
@alice-i-cecile Let me know if we'd like to make any changes based on
these points.
# Objective
`System<f32>` currently does not implement `Eq` even though it should
## Solution
Manually implement `Eq` like other traits are manually implemented
# Objective
- Add a way to combine 2 queries together in a similar way to
`Query::transmute_lens`
- Fixes#1658
## Solution
- Use a similar method to query transmute, but take the intersection of
matched archetypes between the 2 queries and the union of the accesses
to create the new underlying QueryState.
---
## Changelog
- Add query joins
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fix#10876. Improve `Query` and `QueryState`'s docs.
## Solution
Explicitly denote that Query is always guaranteed to return results from
all matching entities once and only once for each entity, and that
iteration order is not guaranteed in any way.
# Objective
Remove Bevy internals from backtraces
## Solution
Executors insert `__rust_begin_short_backtrace` into the callstack
before running a system.
<details>
<summary>Example current output</summary>
```
thread 'Compute Task Pool (3)' panicked at src/main.rs:7:33:
Foo
stack backtrace:
0: rust_begin_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:647:5
1: core::panicking::panic_fmt
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panicking.rs:72:14
2: foo::main::{{closure}}
at ./src/main.rs:7:33
3: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:294:13
4: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run::call_inner
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:661:21
5: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:664:17
6: <bevy_ecs::system::function_system::FunctionSystem<Marker,F> as bevy_ecs::system::system::System>::run_unsafe
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:504:19
7: bevy_ecs::schedule::executor::multi_threaded::ExecutorState::spawn_system_task::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/executor/multi_threaded.rs:621:26
8: core::ops::function::FnOnce::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:250:5
9: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
10: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
11: __rust_try
12: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
13: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
14: bevy_ecs::schedule::executor::multi_threaded::ExecutorState::spawn_system_task::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/executor/multi_threaded.rs:614:23
15: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::future::future::Future>::poll
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:297:9
16: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:588:42
17: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
18: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
19: __rust_try
20: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
21: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
22: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:588:9
23: async_executor::Executor::spawn::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:158:20
24: async_task::raw::RawTask<F,T,S,M>::run::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/raw.rs:550:21
25: core::ops::function::FnOnce::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:250:5
26: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
27: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
28: __rust_try
29: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
30: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
31: async_task::raw::RawTask<F,T,S,M>::run
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/raw.rs:549:23
32: async_task::runnable::Runnable<M>::run
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/runnable.rs:781:18
33: async_executor::Executor::run::{{closure}}::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:254:21
34: <futures_lite::future::Or<F1,F2> as core::future::future::Future>::poll
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:449:33
35: async_executor::Executor::run::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:261:32
36: futures_lite::future::block_on::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:99:19
37: std:🧵:local::LocalKey<T>::try_with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:286:16
38: std:🧵:local::LocalKey<T>::with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:262:9
39: futures_lite::future::block_on
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:78:5
40: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:180:37
41: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
42: __rust_try
43: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
44: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
45: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:174:43
46: std:🧵:local::LocalKey<T>::try_with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:286:16
47: std:🧵:local::LocalKey<T>::with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:262:9
48: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:167:25
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Encountered a panic in system `foo::main::{{closure}}`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
get on your knees and beg mommy for forgiveness you pervert~ 💖
```
</details>
<details>
<summary>Example output with this PR</summary>
```
Panic at src/main.rs:7:33:
Foo
stack backtrace:
0: rust_begin_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:647:5
1: core::panicking::panic_fmt
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panicking.rs:72:14
2: foo::main::{{closure}}
at ./src/main.rs:7:59
3: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:294:13
4: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run::call_inner
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:661:21
5: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:664:17
6: <bevy_ecs::system::function_system::FunctionSystem<Marker,F> as bevy_ecs::system::system::System>::run_unsafe
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:504:19
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Encountered a panic in system `foo::main::{{closure}}`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
```
</details>
Full backtraces (`RUST_BACKTRACE=full`) are unchanged.
## Alternative solutions
Write a custom panic hook. This could potentially let use exclude a few
more callstack frames but requires a dependency on `backtrace` and is
incompatible with user-provided panic hooks.
---
## Changelog
- Backtraces now exclude many Bevy internals (unless
`RUST_BACKTRACE=full` is used)
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Fix missing `TextBundle` (and many others) which are present in the main
crate as default features but optional in the sub-crate. See:
- https://docs.rs/bevy/0.13.0/bevy/ui/node_bundles/index.html
- https://docs.rs/bevy_ui/0.13.0/bevy_ui/node_bundles/index.html
~~There are probably other instances in other crates that I could track
down, but maybe "all-features = true" should be used by default in all
sub-crates? Not sure.~~ (There were many.) I only noticed this because
rust-analyzer's "open docs" features takes me to the sub-crate, not the
main one.
## Solution
Add "all-features = true" to docs.rs metadata for crates that use
features.
## Changelog
### Changed
- Unified features documented on docs.rs between main crate and
sub-crates
# Objective
Make bevy_utils less of a compilation bottleneck. Tackle #11478.
## Solution
* Move all of the directly reexported dependencies and move them to
where they're actually used.
* Remove the UUID utilities that have gone unused since `TypePath` took
over for `TypeUuid`.
* There was also a extraneous bytemuck dependency on `bevy_core` that
has not been used for a long time (since `encase` became the primary way
to prepare GPU buffers).
* Remove the `all_tuples` macro reexport from bevy_ecs since it's
accessible from `bevy_utils`.
---
## Changelog
Removed: Many of the reexports from bevy_utils (petgraph, uuid, nonmax,
smallvec, and thiserror).
Removed: bevy_core's reexports of bytemuck.
## Migration Guide
bevy_utils' reexports of petgraph, uuid, nonmax, smallvec, and thiserror
have been removed.
bevy_core' reexports of bytemuck's types has been removed.
Add them as dependencies in your own crate instead.
# Objective
Following #10756, we're now using raw pointers in BundleInserter and
BundleSpawner. This is primarily to get around the need to split the
borrow on the World, but it leaves a lot to be desired in terms of
safety guarantees. There's no type level guarantee the code can't
dereference a null pointer, and it's restoring them to borrows fairly
liberally within the associated functions.
## Solution
* Replace the pointers with `NonNull` and a new `bevy_ptr::ConstNonNull`
that only allows conversion back to read-only borrows
* Remove the closure to avoid potentially aliasing through the closure
by restructuring the match expression.
* Move all conversions back into borrows as far up as possible to ensure
that the borrow checker is at least locally followed.
# Objective
`initialize_resource<T>` and it's non-send equivalent is only used in
two locations each. Fix#6285.
## Solution
Remove them, replace their calls with their internals. Cut down on a bit
of generic codegen.
This does mean that `initialize_resource_internal` is now `pub(crate)`,
but that's likely OK given that only one variant will remain once
NonSend resources are removed from the World.
# Objective
When doing a final pass for #3362, it appeared that `ComponentStorage`
as a trait, the two types implementing it, and the associated type on
`Component` aren't really necessary anymore. This likely was due to an
earlier constraint on the use of consts in traits, but that definitely
doesn't seem to be a problem in Rust 1.76.
## Solution
Remove them.
---
## Changelog
Changed: `Component::Storage` has been replaced with
`Component::STORAGE_TYPE` as a const.
Removed: `bevy::ecs::component::ComponentStorage` trait
Removed: `bevy::ecs::component::TableStorage` struct
Removed: `bevy::ecs::component::SparseSetStorage` struct
## Migration Guide
If you were manually implementing `Component` instead of using the
derive macro, replace the associated `Storage` associated type with the
`STORAGE_TYPE` const:
```rust
// in Bevy 0.13
impl Component for MyComponent {
type Storage = TableStorage;
}
// in Bevy 0.14
impl Component for MyComponent {
const STORAGE_TYPE: StorageType = StorageType::Table;
}
```
Component is no longer object safe. If you were relying on `&dyn
Component`, `Box<dyn Component>`, etc. please [file an issue
](https://github.com/bevyengine/bevy/issues) to get [this
change](https://github.com/bevyengine/bevy/pull/12311) reverted.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
- Explain it is flushed in the same schedule run (was not obvious to me)
- Point to `apply_deferred` example
- Remove mentions of `System::apply_deferred` and
`Schedule::apply_deferred` which are probably too low level for the most
users
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- The doc example for `World::run_system_with_input` mistakenly
indicates that systems share state
- Some of the doc example code is unnecessary and/or could be cleaned up
## Solution
Replace the incorrect result value for the correct one in the doc
example. I also went with an explicit `assert_eq` check as it presents
the same information but can be validated by CI via doc tests.
Also removed some unnecessary code, such as the `Resource` derives on
`Counter`. In fact, I just replaced `Counter` with a `u8` in the
`Local`. I think it makes the example a little cleaner.
---
## Changelog
- Update docs for `World::run_system` and `World::run_system_with_input`
# Objective
Adoption of #2104 and #11843. The `Option<usize>` wastes 3-7 bytes of
memory per potential entry, and represents a scaling memory overhead as
the ID space grows.
The goal of this PR is to reduce memory usage without significantly
impacting common use cases.
Co-Authored By: @NathanSWard
Co-Authored By: @tygyh
## Solution
Replace `usize` in `SparseSet`'s sparse array with
`nonmax::NonMaxUsize`. NonMaxUsize wraps a NonZeroUsize, and applies a
bitwise NOT to the value when accessing it. This allows the compiler to
niche the value and eliminate the extra padding used for the `Option`
inside the sparse array, while moving the niche value from 0 to
usize::MAX instead.
Checking the [diff in x86 generated
assembly](6e4da653cc),
this change actually results in fewer instructions generated. One
potential downside is that it seems to have moved a load before a
branch, which means we may be incurring a cache miss even if the element
is not there.
Note: unlike #2104 and #11843, this PR only targets the metadata stores
for the ECS and not the component storage itself. Due to #9907 targeting
`Entity::generation` instead of `Entity::index`, `ComponentSparseSet`
storing only up to `u32::MAX` elements would become a correctness issue.
This will come with a cost when inserting items into the SparseSet, as
now there is a potential for a panic. These cost are really only
incurred when constructing a new Table, Archetype, or Resource that has
never been seen before by the World. All operations that are fairly cold
and not on any particular hotpath, even for command application.
---
## Changelog
Changed: `SparseSet` now can only store up to `usize::MAX - 1` elements
instead of `usize::MAX`.
Changed: `SparseSet` now uses 33-50% less memory overhead per stored
item.
# Objective
Fixes https://github.com/bevyengine/bevy/issues/11628
## Migration Guide
`Command` and `CommandQueue` have migrated from `bevy_ecs::system` to
`bevy_ecs::world`, so `use bevy_ecs::world::{Command, CommandQueue};`
when necessary.
# Objective
bevy_ecs has been developed with a de facto assumption that `Entity` is
to be treated as an opaque identifier by external users, and that its
internal representation is readable but in no way guaranteed to be
stable between versions of bevy_ecs.
This hasn't been clear to users, and the functions on the type that
expose its guts speak a different story.
## Solution
Explicitly document the lack of stability here and define internal
representation changes as a non-breaking change under SemVer. Give it
the same treatment that the standard lib gives `TypeId`.
# Objective
- Fix mismatch between the `Component` trait method and the `World`
method.
## Solution
- Replace init_component_info with register_component_hooks.
# Objective
- Provide a reliable and performant mechanism to allows users to keep
components synchronized with external sources: closing/opening sockets,
updating indexes, debugging etc.
- Implement a generic mechanism to provide mutable access to the world
without allowing structural changes; this will not only be used here but
is a foundational piece for observers, which are key for a performant
implementation of relations.
## Solution
- Implement a new type `DeferredWorld` (naming is not important,
`StaticWorld` is also suitable) that wraps a world pointer and prevents
user code from making any structural changes to the ECS; spawning
entities, creating components, initializing resources etc.
- Add component lifecycle hooks `on_add`, `on_insert` and `on_remove`
that can be assigned callbacks in user code.
---
## Changelog
- Add new `DeferredWorld` type.
- Add new world methods: `register_component::<T>` and
`register_component_with_descriptor`. These differ from `init_component`
in that they provide mutable access to the created `ComponentInfo` but
will panic if the component is already in any archetypes. These
restrictions serve two purposes:
1. Prevent users from defining hooks for components that may already
have associated hooks provided in another plugin. (a use case better
served by observers)
2. Ensure that when an `Archetype` is created it gets the appropriate
flags to early-out when triggering hooks.
- Add methods to `ComponentInfo`: `on_add`, `on_insert` and `on_remove`
to be used to register hooks of the form `fn(DeferredWorld, Entity,
ComponentId)`
- Modify `BundleInserter`, `BundleSpawner` and `EntityWorldMut` to
trigger component hooks when appropriate.
- Add bit flags to `Archetype` indicating whether or not any contained
components have each type of hook, this can be expanded for other flags
as needed.
- Add `component_hooks` example to illustrate usage. Try it out! It's
fun to mash keys.
## Safety
The changes to component insertion, removal and deletion involve a large
amount of unsafe code and it's fair for that to raise some concern. I
have attempted to document it as clearly as possible and have confirmed
that all the hooks examples are accepted by `cargo miri` as not causing
any undefined behavior. The largest issue is in ensuring there are no
outstanding references when passing a `DeferredWorld` to the hooks which
requires some use of raw pointers (as was already happening to some
degree in those places) and I have taken some time to ensure that is the
case but feel free to let me know if I've missed anything.
## Performance
These changes come with a small but measurable performance cost of
between 1-5% on `add_remove` benchmarks and between 1-3% on `insert`
benchmarks. One consideration to be made is the existence of the current
`RemovedComponents` which is on average more costly than the addition of
`on_remove` hooks due to the early-out, however hooks doesn't completely
remove the need for `RemovedComponents` as there is a chance you want to
respond to the removal of a component that already has an `on_remove`
hook defined in another plugin, so I have not removed it here. I do
intend to deprecate it with the introduction of observers in a follow up
PR.
## Discussion Questions
- Currently `DeferredWorld` implements `Deref` to `&World` which makes
sense conceptually, however it does cause some issues with rust-analyzer
providing autocomplete for `&mut World` references which is annoying.
There are alternative implementations that may address this but involve
more code churn so I have attempted them here. The other alternative is
to not implement `Deref` at all but that leads to a large amount of API
duplication.
- `DeferredWorld`, `StaticWorld`, something else?
- In adding support for hooks to `EntityWorldMut` I encountered some
unfortunate difficulties with my desired API. If commands are flushed
after each call i.e. `world.spawn() // flush commands .insert(A) //
flush commands` the entity may be despawned while `EntityWorldMut` still
exists which is invalid. An alternative was then to add
`self.world.flush_commands()` to the drop implementation for
`EntityWorldMut` but that runs into other problems for implementing
functions like `into_unsafe_entity_cell`. For now I have implemented a
`.flush()` which will flush the commands and consume `EntityWorldMut` or
users can manually run `world.flush_commands()` after using
`EntityWorldMut`.
- In order to allowing querying on a deferred world we need
implementations of `WorldQuery` to not break our guarantees of no
structural changes through their `UnsafeWorldCell`. All our
implementations do this, but there isn't currently any safety
documentation specifying what is or isn't allowed for an implementation,
just for the caller, (they also shouldn't be aliasing components they
didn't specify access for etc.) is that something we should start doing?
(see 10752)
Please check out the example `component_hooks` or the tests in
`bundle.rs` for usage examples. I will continue to expand this
description as I go.
See #10839 for a more ergonomic API built on top of this one that isn't
subject to the same restrictions and supports `SystemParam` dependency
injection.
# Objective
- In #9623 I forgot to change the `FromWorld` requirement for
`ReflectResource`, fix that;
- Fix#12129
## Solution
- Use the same approach as in #9623 to try using `FromReflect` and
falling back to the `ReflectFromWorld` contained in the `TypeRegistry`
provided
- Just reflect `Resource` on `State<S>` since now that's possible
without introducing new bounds.
---
## Changelog
- `ReflectResource`'s `FromType<T>` implementation no longer requires
`T: FromWorld`, but instead now requires `FromReflect`.
- `ReflectResource::insert`, `ReflectResource::apply_or_insert` and
`ReflectResource::copy` now take an extra `&TypeRegistry` parameter.
## Migration Guide
- Users of `#[reflect(Resource)]` will need to also implement/derive
`FromReflect` (should already be the default).
- Users of `#[reflect(Resource)]` may now want to also add `FromWorld`
to the list of reflected traits in case their `FromReflect`
implementation may fail.
- Users of `ReflectResource` will now need to pass a `&TypeRegistry` to
its `insert`, `apply_or_insert` and `copy` methods.
# Objective
`downcast-rs` is not used within bevy_ecs. This is probably a remnant
from before Schedule v3 landed, since stages needed the downcasting.
## Solution
Remove it.
# Objective
Memory usage optimisation
## Solution
`HashMap` and `HashSet`'s keys are immutable. So using mutable types
like `String`, `Vec<T>`, or `PathBuf` as a key is a waste of memory:
they have an extra `usize` for their capacity and may have spare
capacity.
This PR replaces these types by their immutable equivalents `Box<str>`,
`Box<[T]>`, and `Box<Path>`.
For more context, I recommend watching the [Use Arc Instead of
Vec](https://www.youtube.com/watch?v=A4cKi7PTJSs) video.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Avoid misspellings throughout the codebase by using
[`typos`](https://github.com/crate-ci/typos) in CI
Inspired by https://github.com/gfx-rs/wgpu/pull/5191
Typos is a minimal code speller written in rust that finds and corrects
spelling mistakes among source code.
- Fast enough to run on monorepos
- Low false positives so you can run on PRs
## Solution
- Use
[typos-action](https://github.com/marketplace/actions/typos-action) in
CI
- Add how to use typos in the Contribution Guide
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Right now when using egui, systems are inserted without any identifier
and to the root. I'd like to name those systems and insert them as
children to a root entity. This helps to keep the editor organized.
## Solution
- Although the `SystemId` is documented as an opaque type, examples
depicted above benefit from tear down of the abstraction.
---
## Changelog
### Added
- Implemented `From<SystemId>` for `Entity`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Add Archetype::component_count utility method
# Objective
I wanted a method to count components on an archetype without iterating
over them.
## Solution
Added `Archetype::component_count`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
The multi-threaded executor currently runs in a dedicated task on a
single thread. When a system finishes running, it needs to notify that
task and wait for the thread to be available and running before the
executor can process the completion.
See #8304
## Solution
Run the multi-threaded executor at the end of each system task. This
allows it to run immediately instead of needing to wait for the main
thread to wake up. Move the mutable executor state into a separate
struct and wrap it in a mutex so it can be shared among the worker
threads.
While this should be faster in theory, I don't actually know how to
measure the performance impact myself.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
- A tiny nit I noticed; I think the type of these function is
`EntityCommand`, not `Command`
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
# Objective
- Add the new `-Zcheck-cfg` checks to catch more warnings
- Fixes#12091
## Solution
- Create a new `cfg-check` to the CI that runs `cargo check -Zcheck-cfg
--workspace` using cargo nightly (and fails if there are warnings)
- Fix all warnings generated by the new check
---
## Changelog
- Remove all redundant imports
- Fix cfg wasm32 targets
- Add 3 dead code exceptions (should StandardColor be unused?)
- Convert ios_simulator to a feature (I'm not sure if this is the right
way to do it, but the check complained before)
## Migration Guide
No breaking changes
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#11821.
## Solution
* Run `System::apply_deferred` in `System::run` after executing the
system.
* Switch to using `System::run_unsafe` in `SingleThreadedExecutor` to
preserve the current behavior.
* Remove the `System::apply_deferred` in `SimpleExecutor` as it's now
redundant.
* Remove the `System::apply_deferred` when running one-shot systems, as
it's now redundant.
---
## Changelog
Changed: `System::run` will now immediately apply deferred system params
after running the system.
## Migration Guide
`System::run` will now always run `System::apply_deferred` immediately
after running the system now. If you were running systems and then
applying their deferred buffers at a later point in time, you can
eliminate the latter.
```rust
// in 0.13
system.run(world);
// .. sometime later ...
system.apply_deferred(world);
// in 0.14
system.run(world);
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Since #9822, `SimpleExecutor` panics when an automatic sync point is
inserted:
```rust
let mut sched = Schedule::default();
sched.set_executor_kind(ExecutorKind::Simple);
sched.add_systems((|_: Commands| (), || ()).chain());
sched.run(&mut World::new());
```
```
System's param_state was not found. Did you forget to initialize this system before running it?
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Encountered a panic in system `bevy_ecs::schedule::executor::apply_deferred`!
```
## Solution
Don't try to run the `apply_deferred` system.
# Objective
- Part of #11590
- Fix `unsafe_op_in_unsafe_fn` for trivial cases in bevy_ecs
## Solution
Fix `unsafe_op_in_unsafe_fn` in bevy_ecs for trivial cases, i.e., add an
`unsafe` block when the safety comment already exists or add a comment
like "The invariants are uphold by the caller".
---------
Co-authored-by: James Liu <contact@jamessliu.com>
## Objective
Always have `some_system.into_system().type_id() ==
some_system.into_system_set().system_type().unwrap()`.
System sets have a `fn system_type() -> Option<TypeId>` that is
implemented by `SystemTypeSet` to returning the TypeId of the system's
function type. This was implemented in
https://github.com/bevyengine/bevy/pull/7715 and is used in
`bevy_mod_debugdump` to handle `.after(function)` constraints.
Back then, `System::type_id` always also returned the type id of the
function item, not of `FunctionSystem<M, F>`.
https://github.com/bevyengine/bevy/pull/11728 changes the behaviour of
`System::type_id` so that it returns the id of the
`FunctionSystem`/`ExclusiveFunctionSystem` wrapper, but it did not
change `SystemTypeSet::system_type`, so doing the lookup breaks in
`bevy_mod_debugdump`.
## Solution
Change `IntoSystemSet` for functions to return a
`SystemTypeSet<FunctionSystem>` /
`SystemTypeSet<ExclusiveFunctionSystem>` instead of `SystemTypeSet<F>`.
Fixes#12016.
Bump version after release
This PR has been auto-generated
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
We deprecated quite a few APIs in 0.13. 0.13 has shipped already. It
should be OK to remove them in 0.14's release. Fixes#4059. Fixes#9011.
## Solution
Remove them.
# Objective
* Fixes#11932 (performance impact when stepping is disabled)
## Solution
The `Option<FixedBitSet>` argument added to `ScheduleExecutor::run()` in
#8453 caused a measurable performance impact even when stepping is
disabled. This can be seen by the benchmark of running `Schedule:run()`
on an empty schedule in a tight loop
(https://github.com/bevyengine/bevy/issues/11932#issuecomment-1950970236).
I was able to get the same performance results as on 0.12.1 by changing
the argument
`ScheduleExecutor::run()` from `Option<FixedBitSet>` to
`Option<&FixedBitSet>`. The down-side of this change is that
`Schedule::run()` now takes about 6% longer (3.7319 ms vs 3.9855ns) when
stepping is enabled
---
## Changelog
* Change `ScheduleExecutor::run()` `_skipped_systems` from
`Option<FixedBitSet>` to `Option<&FixedBitSet>`
* Added a few benchmarks to measure `Schedule::run()` performance with
various executors
# Objective
There's a repeating pattern of `ThreadLocal<Cell<Vec<T>>>` which is very
useful for low overhead, low contention multithreaded queues that have
cropped up in a few places in the engine. This pattern is surprisingly
useful when building deferred mutation across multiple threads, as noted
by it's use in `ParallelCommands`.
However, `ThreadLocal<Cell<Vec<T>>>` is not only a mouthful, it's also
hard to ensure the thread-local queue is replaced after it's been
temporarily removed from the `Cell`.
## Solution
Wrap the pattern into `bevy_utils::Parallel<T>` which codifies the
entire pattern and ensures the user follows the contract. Instead of
fetching indivdual cells, removing the value, mutating it, and replacing
it, `Parallel::get` returns a `ParRef<'a, T>` which contains the
temporarily removed value and a reference back to the cell, and will
write the mutated value back to the cell upon being dropped.
I would like to use this to simplify the remaining part of #4899 that
has not been adopted/merged.
---
## Changelog
TODO
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
`update_archetype_component_access` was removed from queries in #9774,
but some documentation still refers to it.
## Solution
Update the documentation. Since a bunch of these were in SAFETY comments
it would be nice if someone who knows the details better could check
that the rest of those comments are still valid.
# Objective
- There are multiple instances of `let Some(x) = ... else { None };`
throughout the project.
- Because `Option<T>` implements
[`Try`](https://doc.rust-lang.org/stable/std/ops/trait.Try.html), it can
use the question mark `?` operator.
## Solution
- Use question mark operator instead of `let Some(x) = ... else { None
}`.
---
There was another PR that did a similar thing a few weeks ago, but I
couldn't find it.
# Objective
At the start of every schedule run, there's currently a guaranteed piece
of overhead as the async executor spawns the MultithreadeExecutor task
onto one of the ComputeTaskPool threads.
## Solution
Poll the executor once to immediately schedule systems without waiting
for the async executor, then spawn the task if and only if the executor
does not immediately terminate.
On a similar note, having the executor task immediately start executing
a system in the same async task might yield similar results over a
broader set of cases. However, this might be more involved, and may need
a solution like #8304.
# Objective
When applying a command, we currently use double indirection for the
world reference `&mut Option<&mut World>`. Since this is used across a
`fn` pointer boundary, this can't get optimized away.
## Solution
Reborrow the world reference and pass `Option<&mut World>` instead.
# Objective
Bevy's change detection functionality is invaluable for writing robust
apps, but it only works in the context of systems and exclusive systems.
Oftentimes it is necessary to detect changes made in earlier code
without having to place the code in separate systems, but it is not
currently possible to do so since there is no way to set the value of
`World::last_change_tick`.
`World::clear_trackers` allows you to update the change tick, but this
has unintended side effects, since it irreversibly affects the behavior
of change and removal detection for the entire app.
## Solution
Add a method `World::last_change_tick_scope`. This allows you to set
`last_change_tick` to a specific value for a region of code. To ensure
that misuse doesn't break unrelated functions, we restore the world's
original change tick at the end of the provided scope.
### Example
A function that uses this to run an update loop repeatedly, allowing
each iteration of the loop to react to changes made in the previous loop
iteration.
```rust
fn update_loop(
world: &mut World,
mut update_fn: impl FnMut(&mut World) -> std::ops::ControlFlow<()>,
) {
let mut last_change_tick = world.last_change_tick();
// Repeatedly run the update function until it requests a break.
loop {
// Update once.
let control_flow = world.last_change_tick_scope(last_change_tick, |world| {
update_fn(world)
});
// End the loop when the closure returns `ControlFlow::Break`.
if control_flow.is_break() {
break;
}
// Increment the change tick so the next update can detect changes from this update.
last_change_tick = world.change_tick();
world.increment_change_tick();
}
}
```
---
## Changelog
+ Added `World::last_change_tick_scope`, which allows you to specify the
reference for change detection within a certain scope.
# Objective
Reduce the size of `bevy_utils`
(https://github.com/bevyengine/bevy/issues/11478)
## Solution
Move `EntityHash` related types into `bevy_ecs`. This also allows us
access to `Entity`, which means we no longer need `EntityHashMap`'s
first generic argument.
---
## Changelog
- Moved `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` into `bevy::ecs::entity::hash` .
- Removed `EntityHashMap`'s first generic argument. It is now hardcoded
to always be `Entity`.
## Migration Guide
- Uses of `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` now have to be imported from `bevy::ecs::entity::hash`.
- Uses of `EntityHashMap` no longer have to specify the first generic
parameter. It is now hardcoded to always be `Entity`.
# Objective
It would be useful to be able to inspect a `QueryState`'s accesses so we
can detect when the data it accesses changes without having to iterate
it. However there are two things preventing this:
* These accesses are unnecessarily encapsulated.
* `Has<T>` indirectly accesses `T`, but does not register it.
## Solution
* Expose accesses and matches used by `QueryState`.
* Add the notion of "archetypal" accesses, which are not accessed
directly, but whose presence in an archetype affects a query result.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
I want to keep track of despawned entities.
I am aware of
[`RemovedComponents`](https://docs.rs/bevy/0.12.1/bevy/ecs/prelude/struct.RemovedComponents.html).
However, the docs don't explicitly mention that despawned entities are
also included in this event iterator.
I searched through the bevy tests to find `removal_tracking` in
`crates/bevy_ecs/src/system/mod.rs` that confirmed the behavior:
```rust
...
assert_eq!(
removed_i32.read().collect::<Vec<_>>(),
&[despawned.0],
"despawning causes the correct entity to show up in the 'RemovedComponent' system parameter."
);
...
```
## Solution
- Explicitly mention this behavior in docs.
[`ScheduleLabel`] derive macro uses "ScheduleName" as the trait name by
mistake. This only affects the error message when a user tries to use
the derive macro on a union type. No other code is affected.
# Objective
- Fixes#11679
## Solution
- Added `IntoSystem::system_type_id` which returns the equivalent of
`system.into_system().type_id()` without construction. This allows for
getting the `TypeId` of functions (a function is an unnamed type and
therefore you cannot call `TypeId::of::<apply_deferred::System>()`)
- Added default implementation of `System::type_id` to ensure
consistency between implementations. Some returned `Self`, while others
were returning an inner value instead. This ensures consistency with
`IntoSystem::system_type_id`.
## Migration Guide
If you use `System::type_id()` on function systems (exclusive or not),
ensure you are comparing its value to other `System::type_id()` calls,
or `IntoSystem::system_type_id()`.
This code wont require any changes, because `IntoSystem`'s are directly
compared to each other.
```rust
fn test_system() {}
let type_id = test_system.type_id();
// ...
// No change required
assert_eq!(test_system.type_id(), type_id);
```
Likewise, this code wont, because `System`'s are directly compared.
```rust
fn test_system() {}
let type_id = IntoSystem::into_system(test_system).type_id();
// ...
// No change required
assert_eq!(IntoSystem::into_system(test_system).type_id(), type_id);
```
The below _does_ require a change, since you're comparing a `System`
type to a `IntoSystem` type.
```rust
fn test_system() {}
// Before
assert_eq!(test_system.type_id(), IntoSystem::into_system(test_system).type_id());
// After
assert_eq!(test_system.system_type_id(), IntoSystem::into_system(test_system).type_id());
```
# Objective
- (Partially) Fixes#9904
- Acts on #9910
## Solution
- Deprecated the relevant methods from `Query`, cascading changes as
required across Bevy.
---
## Changelog
- Deprecated `QueryState::get_component_unchecked_mut` method
- Deprecated `Query::get_component` method
- Deprecated `Query::get_component_mut` method
- Deprecated `Query::component` method
- Deprecated `Query::component_mut` method
- Deprecated `Query::get_component_unchecked_mut` method
## Migration Guide
### `QueryState::get_component_unchecked_mut`
Use `QueryState::get_unchecked_manual` and select for the exact
component based on the structure of the exact query as required.
### `Query::(get_)component(_unchecked)(_mut)`
Use `Query::get` and select for the exact component based on the
structure of the exact query as required.
- For mutable access (`_mut`), use `Query::get_mut`
- For unchecked access (`_unchecked`), use `Query::get_unchecked`
- For panic variants (non-`get_`), add `.unwrap()`
## Notes
- `QueryComponentError` can be removed once these deprecated methods are
also removed. Due to an interaction with `thiserror`'s derive macro, it
is not marked as deprecated.
Use `TypeIdMap<T>` instead of `HashMap<TypeId, T>`
- ~~`TypeIdMap` was in `bevy_ecs`. I've kept it there because of
#11478~~
- ~~I haven't swapped `bevy_reflect` over because it doesn't depend on
`bevy_ecs`, but I'd also be happy with moving `TypeIdMap` to
`bevy_utils` and then adding a dependency to that~~
- ~~this is a slight change in the public API of
`DrawFunctionsInternal`, does this need to go in the changelog?~~
## Changelog
- moved `TypeIdMap` to `bevy_utils`
- changed `DrawFunctionsInternal::indices` to `TypeIdMap`
## Migration Guide
- `TypeIdMap` now lives in `bevy_utils`
- `DrawFunctionsInternal::indices` now uses a `TypeIdMap`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.
## Solution
Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
# Objective
Add interactive system debugging capabilities to bevy, providing
step/break/continue style capabilities to running system schedules.
* Original implementation: #8063
- `ignore_stepping()` everywhere was too much complexity
* Schedule-config & Resource discussion: #8168
- Decided on selective adding of Schedules & Resource-based control
## Solution
Created `Stepping` Resource. This resource can be used to enable
stepping on a per-schedule basis. Systems within schedules can be
individually configured to:
* AlwaysRun: Ignore any stepping state and run every frame
* NeverRun: Never run while stepping is enabled
- this allows for disabling of systems while debugging
* Break: If we're running the full frame, stop before this system is run
Stepping provides two modes of execution that reflect traditional
debuggers:
* Step-based: Only execute one system at a time
* Continue/Break: Run all systems, but stop before running a system
marked as Break
### Demo
https://user-images.githubusercontent.com/857742/233630981-99f3bbda-9ca6-4cc4-a00f-171c4946dc47.mov
Breakout has been modified to use Stepping. The game runs normally for a
couple of seconds, then stepping is enabled and the game appears to
pause. A list of Schedules & Systems appears with a cursor at the first
System in the list. The demo then steps forward full frames using the
spacebar until the ball is about to hit a brick. Then we step system by
system as the ball impacts a brick, showing the cursor moving through
the individual systems. Finally the demo switches back to frame stepping
as the ball changes course.
### Limitations
Due to architectural constraints in bevy, there are some cases systems
stepping will not function as a user would expect.
#### Event-driven systems
Stepping does not support systems that are driven by `Event`s as events
are flushed after 1-2 frames. Although game systems are not running
while stepping, ignored systems are still running every frame, so events
will be flushed.
This presents to the user as stepping the event-driven system never
executes the system. It does execute, but the events have already been
flushed.
This can be resolved by changing event handling to use a buffer for
events, and only dropping an event once all readers have read it.
The work-around to allow these systems to properly execute during
stepping is to have them ignore stepping:
`app.add_systems(event_driven_system.ignore_stepping())`. This was done
in the breakout example to ensure sound played even while stepping.
#### Conditional Systems
When a system is stepped, it is given an opportunity to run. If the
conditions of the system say it should not run, it will not.
Similar to Event-driven systems, if a system is conditional, and that
condition is only true for a very small time window, then stepping the
system may not execute the system. This includes depending on any sort
of external clock.
This exhibits to the user as the system not always running when it is
stepped.
A solution to this limitation is to ensure any conditions are consistent
while stepping is enabled. For example, all systems that modify any
state the condition uses should also enable stepping.
#### State-transition Systems
Stepping is configured on the per-`Schedule` level, requiring the user
to have a `ScheduleLabel`.
To support state-transition systems, bevy generates needed schedules
dynamically. Currently it’s very difficult (if not impossible, I haven’t
verified) for the user to get the labels for these schedules.
Without ready access to the dynamically generated schedules, and a
resolution for the `Event` lifetime, **stepping of the state-transition
systems is not supported**
---
## Changelog
- `Schedule::run()` updated to consult `Stepping` Resource to determine
which Systems to run each frame
- Added `Schedule.label` as a `BoxedSystemLabel`, along with supporting
`Schedule::set_label()` and `Schedule::label()` methods
- `Stepping` needed to know which `Schedule` was running, and prior to
this PR, `Schedule` didn't track its own label
- Would have preferred to add `Schedule::with_label()` and remove
`Schedule::new()`, but this PR touches enough already
- Added calls to `Schedule.set_label()` to `App` and `World` as needed
- Added `Stepping` resource
- Added `Stepping::begin_frame()` system to `MainSchedulePlugin`
- Run before `Main::run_main()`
- Notifies any `Stepping` Resource a new render frame is starting
## Migration Guide
- Add a call to `Schedule::set_label()` for any custom `Schedule`
- This is only required if the `Schedule` will be stepped
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fix an issue where events are not being dropped after being read. I
believe #10077 introduced this issue. The code currently works as
follows:
1. `EventUpdateSignal` is **shared for all event types**
2. During the fixed update phase, `EventUpdateSignal` is set to true
3. `event_update_system`, **unique per event type**, runs to update
Events<T>
4. `event_update_system` reads value of `EventUpdateSignal` to check if
it should update, and then **resets** the value to false
If there are multiple event types, the first `event_update_system` run
will reset the shared `EventUpdateSignal` signal, preventing other
events from being cleared.
## Solution
I've updated the code to have separate signals per event type and added
a shared signal to notify all systems that the time plugin is installed.
## Changelog
- Fixed bug where events were not being dropped
# Objective
- Deriving `Reflect` for some public ChangeDetection/Tick structs in
bevy_ecs
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
# Objective
Fixes: https://github.com/bevyengine/bevy/issues/11549
Add a doctest example of what a custom implementation of an
`EntityMapper` would look like.
(need to wait until https://github.com/bevyengine/bevy/pull/11428 is
merged)
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Hennadii Chernyshchyk <genaloner@gmail.com>
# Objective
- Sending and receiving events of the same type in the same system is a
reasonably common need, generally due to event filtering.
- However, actually doing so is non-trivial, as the borrow checker
simultaneous hates mutable and immutable access.
## Solution
- Demonstrate two sensible patterns for doing so.
- Update the `ManualEventReader` docs to be more clear and link to this
example.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: ickk <git@ickk.io>
# Objective
My motivation are to resolve some of the issues I describe in this
[PR](https://github.com/bevyengine/bevy/issues/11415):
- not being able to easily mapping entities because the current
EntityMapper requires `&mut World` access
- not being able to create my own `EntityMapper` because some components
(`Parent` or `Children`) do not provide any public way of modifying the
inner entities
This PR makes the `MapEntities` trait accept a generic type that
implements `Mapper` to perform the mapping.
This means we don't need to use `EntityMapper` to perform our mapping,
we can use any type that implements `Mapper`. Basically this change is
very similar to what `serde` does. Instead of specifying directly how to
map entities for a given type, we have 2 distinct steps:
- the user implements `MapEntities` to define how the type will be
traversed and which `Entity`s will be mapped
- the `Mapper` defines how the mapping is actually done
This is similar to the distinction between `Serialize` (`MapEntities`)
and `Serializer` (`Mapper`).
This allows networking library to map entities without having to use the
existing `EntityMapper` (which requires `&mut World` access and the use
of `world_scope()`)
## Migration Guide
- The existing `EntityMapper` (notably used to replicate `Scenes` across
different `World`s) has been renamed to `SceneEntityMapper`
- The `MapEntities` trait now works with a generic `EntityMapper`
instead of the specific struct `EntityMapper`.
Calls to `fn map_entities(&mut self, entity_mapper: &mut EntityMapper)`
need to be updated to
`fn map_entities<M: EntityMapper>(&mut self, entity_mapper: &mut M)`
- The new trait `EntityMapper` has been added to the prelude
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: UkoeHB <37489173+UkoeHB@users.noreply.github.com>
# Objective
Fixes#11311
## Solution
Adds an example to the documentation for `par_iter_mut`. I didn't add
any examples to `par_iter`, because I couldn't think of a good example
and I figure users can infer that `par_iter` and `par_iter_mut` are
similar.
# Objective
It's sometimes desirable to get a `Res<T>` rather than `&T` from
`World::get_resource`.
Alternative to #9940, partly adresses #9926
## Solution
added additional methods to `World` and `UnsafeWorldCell` to retrieve a
resource wrapped in a `Res`.
- `UnsafeWorldCell::get_resource_ref`
- `World::get_resource_ref`
- `World::resource_ref`
I can change it so `World::resource_mut` returns `ResMut` instead of
`Mut` as well if that's desired, but that could also be added later in a
seperate pr.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
# Objective
While working on #11527 I spotted that the internal field for the label
of a `Schedule` is called `name`. Using `label` seems more in line with
the other naming across Bevy.
## Solution
Renaming the field was straightforward since it's not exposed outside of
the module. This also means a changelog or migration guide isn't
necessary.
# Objective
- `World::get_resource`'s comment on it's `unsafe` usage meant to say
"mutably" but instead said "immutably."
- Fixes#11430.
## Solution
- Replace "immutably" with "mutably."
# Objective
It would be convenient to be able to call functions with `Commands` as a
parameter without having to move your own instance of `Commands`. Since
this struct is composed entirely of references, we can easily get an
owned instance of `Commands` by shortening the lifetime.
## Solution
Add `Commands::reborrow`, `EntiyCommands::reborrow`, and
`Deferred::reborrow`, which returns an owned version of themselves with
a shorter lifetime.
Remove unnecessary lifetimes from `EntityCommands`. The `'w` and `'s`
lifetimes only have to be separate for `Commands` because it's used as a
`SystemParam` -- this is not the case for `EntityCommands`.
---
## Changelog
Added `Commands::reborrow`. This is useful if you have `&mut Commands`
but need `Commands`. Also added `EntityCommands::reborrow` and
`Deferred:reborrow` which serve the same purpose.
## Migration Guide
The lifetimes for `EntityCommands` have been simplified.
```rust
// Before (Bevy 0.12)
struct MyStruct<'w, 's, 'a> {
commands: EntityCommands<'w, 's, 'a>,
}
// After (Bevy 0.13)
struct MyStruct<'a> {
commands: EntityCommands<'a>,
}
```
The method `EntityCommands::commands` now returns `Commands` rather than
`&mut Commands`.
```rust
// Before (Bevy 0.12)
let commands = entity_commands.commands();
commands.spawn(...);
// After (Bevy 0.13)
let mut commands = entity_commands.commands();
commands.spawn(...);
```
# Objective
Document a few common cases of which lifetime is required when using
SystemParam Derive
## Solution
Added a table in the doc comment
---------
Co-authored-by: laund <me@laund.moe>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Adjust bevy internals to utilize `Option<Res<State<S>>>` instead of
`Res<State<S>>`, to allow for adding/removing states at runtime and
avoid unexpected panics.
As requested here:
https://github.com/bevyengine/bevy/pull/10088#issuecomment-1869185413
---
## Changelog
- Changed the use of `world.resource`/`world.resource_mut` to
`world.get_resource`/`world.get_resource_mut` in the
`run_enter_schedule` and `apply_state_transition` systems and handled
the `None` option.
- `in_state` now returns a ` FnMut(Option<Res<State<S>>>) -> bool +
Clone`, returning `false` if the resource doesn't exist.
- `state_exists_and_equals` was marked as deprecated, and now just runs
and returns `in_state`, since their bevhaviour is now identical
- `state_changed` now takes an `Option<Res<State<S>>>` and returns
`false` if it does not exist.
I would like to remove `state_exists_and_equals` fully, but wanted to
ensure that is acceptable before doing so.
---------
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
- `FromType<T>` for `ReflectComponent` and `ReflectBundle` currently
require `T: FromWorld` for two reasons:
- they include a `from_world` method;
- they create dummy `T`s using `FromWorld` and then `apply` a `&dyn
Reflect` to it to simulate `FromReflect`.
- However `FromWorld`/`Default` may be difficult/weird/impractical to
implement, while `FromReflect` is easier and also more natural for the
job.
- See also
https://discord.com/channels/691052431525675048/1146022009554337792
## Solution
- Split `from_world` from `ReflectComponent` and `ReflectBundle` into
its own `ReflectFromWorld` struct.
- Replace the requirement on `FromWorld` in `ReflectComponent` and
`ReflectBundle` with `FromReflect`
---
## Changelog
- `ReflectComponent` and `ReflectBundle` no longer offer a `from_world`
method.
- `ReflectComponent` and `ReflectBundle`'s `FromType<T>` implementation
no longer requires `T: FromWorld`, but now requires `FromReflect`.
- `ReflectComponent::insert`, `ReflectComponent::apply_or_insert` and
`ReflectComponent::copy` now take an extra `&TypeRegistry` parameter.
- There is now a new `ReflectFromWorld` struct.
## Migration Guide
- Existing uses of `ReflectComponent::from_world` and
`ReflectBundle::from_world` will have to be changed to
`ReflectFromWorld::from_world`.
- Users of `#[reflect(Component)]` and `#[reflect(Bundle)]` will need to
also implement/derive `FromReflect`.
- Users of `#[reflect(Component)]` and `#[reflect(Bundle)]` may now want
to also add `FromWorld` to the list of reflected traits in case their
`FromReflect` implementation may fail.
- Users of `ReflectComponent` will now need to pass a `&TypeRegistry` to
its `insert`, `apply_or_insert` and `copy` methods.
# Objective
- Add methods to get Change Ticks for a given resource by type or
ComponentId
- Fixes#11390
The `is_resource_id_changed` requested in the Issue already exists, this
adds their request for `get_resource_change_ticks`
## Solution
- Added two methods to get change ticks by Type or ComponentId
# Objective
Expand the existing `Query` API to support more dynamic use cases i.e.
scripting.
## Prior Art
- #6390
- #8308
- #10037
## Solution
- Create a `QueryBuilder` with runtime methods to define the set of
component accesses for a built query.
- Create new `WorldQueryData` implementations `FilteredEntityMut` and
`FilteredEntityRef` as variants of `EntityMut` and `EntityRef` that
provide run time checked access to the components included in a given
query.
- Add new methods to `Query` to create "query lens" with a subset of the
access of the initial query.
### Query Builder
The `QueryBuilder` API allows you to define a query at runtime. At it's
most basic use it will simply create a query with the corresponding type
signature:
```rust
let query = QueryBuilder::<Entity, With<A>>::new(&mut world).build();
// is equivalent to
let query = QueryState::<Entity, With<A>>::new(&mut world);
```
Before calling `.build()` you also have the opportunity to add
additional accesses and filters. Here is a simple example where we add
additional filter terms:
```rust
let entity_a = world.spawn((A(0), B(0))).id();
let entity_b = world.spawn((A(0), C(0))).id();
let mut query_a = QueryBuilder::<Entity>::new(&mut world)
.with::<A>()
.without::<C>()
.build();
assert_eq!(entity_a, query_a.single(&world));
```
This alone is useful in that allows you to decide which archetypes your
query will match at runtime. However it is also very limited, consider a
case like the following:
```rust
let query_a = QueryBuilder::<&A>::new(&mut world)
// Add an additional access
.data::<&B>()
.build();
```
This will grant the query an additional read access to component B
however we have no way of accessing the data while iterating as the type
signature still only includes &A. For an even more concrete example of
this consider dynamic components:
```rust
let query_a = QueryBuilder::<Entity>::new(&mut world)
// Adding a filter is easy since it doesn't need be read later
.with_id(component_id_a)
// How do I access the data of this component?
.ref_id(component_id_b)
.build();
```
With this in mind the `QueryBuilder` API seems somewhat incomplete by
itself, we need some way method of accessing the components dynamically.
So here's one:
### Query Transmutation
If the problem is not having the component in the type signature why not
just add it? This PR also adds transmute methods to `QueryBuilder` and
`QueryState`. Here's a simple example:
```rust
world.spawn(A(0));
world.spawn((A(1), B(0)));
let mut query = QueryBuilder::<()>::new(&mut world)
.with::<B>()
.transmute::<&A>()
.build();
query.iter(&world).for_each(|a| assert_eq!(a.0, 1));
```
The `QueryState` and `QueryBuilder` transmute methods look quite similar
but are different in one respect. Transmuting a builder will always
succeed as it will just add the additional accesses needed for the new
terms if they weren't already included. Transmuting a `QueryState` will
panic in the case that the new type signature would give it access it
didn't already have, for example:
```rust
let query = QueryState::<&A, Option<&B>>::new(&mut world);
/// This is fine, the access for Option<&A> is less restrictive than &A
query.transmute::<Option<&A>>(&world);
/// Oh no, this would allow access to &B on entities that might not have it, so it panics
query.transmute::<&B>(&world);
/// This is right out
query.transmute::<&C>(&world);
```
This is quite an appealing API to also have available on `Query` however
it does pose one additional wrinkle: In order to to change the iterator
we need to create a new `QueryState` to back it. `Query` doesn't own
it's own state though, it just borrows it, so we need a place to borrow
it from. This is why `QueryLens` exists, it is a place to store the new
state so it can be borrowed when you call `.query()` leaving you with an
API like this:
```rust
fn function_that_takes_a_query(query: &Query<&A>) {
// ...
}
fn system(query: Query<(&A, &B)>) {
let lens = query.transmute_lens::<&A>();
let q = lens.query();
function_that_takes_a_query(&q);
}
```
Now you may be thinking: Hey, wait a second, you introduced the problem
with dynamic components and then described a solution that only works
for static components! Ok, you got me, I guess we need a bit more:
### Filtered Entity References
Currently the only way you can access dynamic components on entities
through a query is with either `EntityMut` or `EntityRef`, however these
can access all components and so conflict with all other accesses. This
PR introduces `FilteredEntityMut` and `FilteredEntityRef` as
alternatives that have additional runtime checking to prevent accessing
components that you shouldn't. This way you can build a query with a
`QueryBuilder` and actually access the components you asked for:
```rust
let mut query = QueryBuilder::<FilteredEntityRef>::new(&mut world)
.ref_id(component_id_a)
.with(component_id_b)
.build();
let entity_ref = query.single(&world);
// Returns Some(Ptr) as we have that component and are allowed to read it
let a = entity_ref.get_by_id(component_id_a);
// Will return None even though the entity does have the component, as we are not allowed to read it
let b = entity_ref.get_by_id(component_id_b);
```
For the most part these new structs have the exact same methods as their
non-filtered equivalents.
Putting all of this together we can do some truly dynamic ECS queries,
check out the `dynamic` example to see it in action:
```
Commands:
comp, c Create new components
spawn, s Spawn entities
query, q Query for entities
Enter a command with no parameters for usage.
> c A, B, C, Data 4
Component A created with id: 0
Component B created with id: 1
Component C created with id: 2
Component Data created with id: 3
> s A, B, Data 1
Entity spawned with id: 0v0
> s A, C, Data 0
Entity spawned with id: 1v0
> q &Data
0v0: Data: [1, 0, 0, 0]
1v0: Data: [0, 0, 0, 0]
> q B, &mut Data
0v0: Data: [2, 1, 1, 1]
> q B || C, &Data
0v0: Data: [2, 1, 1, 1]
1v0: Data: [0, 0, 0, 0]
```
## Changelog
- Add new `transmute_lens` methods to `Query`.
- Add new types `QueryBuilder`, `FilteredEntityMut`, `FilteredEntityRef`
and `QueryLens`
- `update_archetype_component_access` has been removed, archetype
component accesses are now determined by the accesses set in
`update_component_access`
- Added method `set_access` to `WorldQuery`, this is called before
`update_component_access` for queries that have a restricted set of
accesses, such as those built by `QueryBuilder` or `QueryLens`. This is
primarily used by the `FilteredEntity*` variants and has an empty trait
implementation.
- Added method `get_state` to `WorldQuery` as a fallible version of
`init_state` when you don't have `&mut World` access.
## Future Work
Improve performance of `FilteredEntityMut` and `FilteredEntityRef`,
currently they have to determine the accesses a query has in a given
archetype during iteration which is far from ideal, especially since we
already did the work when matching the archetype in the first place. To
avoid making more internal API changes I have left it out of this PR.
---------
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
# Objective
- Update async channel to v2.
## Solution
- async channel doesn't support `send_blocking` on wasm anymore. So
don't compile the pipelined rendering plugin on wasm anymore.
- Replaces https://github.com/bevyengine/bevy/pull/10405
## Migration Guide
- The `PipelinedRendering` plugin is no longer exported on wasm. If you
are including it in your wasm builds you should remove it.
```rust
#[cfg(all(not(target_arch = "wasm32"))]
app.add_plugins(bevy_render::pipelined_rendering::PipelinedRenderingPlugin);
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Based on discussion after #11268 was merged:
Instead of panicking should the impl of `TypeId::hash` change
significantly, have a fallback and detect this in a test.
# Objective
`TypeId` contains a high-quality hash. Whenever a lookup based on a
`TypeId` is performed (e.g. to insert/remove components), the hash is
run through a second hash function. This is unnecessary.
## Solution
Skip re-hashing `TypeId`s.
In my
[testing](https://gist.github.com/SpecificProtagonist/4b49ad74c6b82b0aedd3b4ea35121be8),
this improves lookup performance consistently by 10%-15% (of course, the
lookup is only a small part of e.g. a bundle insertion).
# Objective
The purpose of this PR is to begin putting together a unified identifier
structure that can be used by entities and later components (as
entities) as well as relationship pairs for relations, to enable all of
these to be able to use the same storages. For the moment, to keep
things small and focused, only `Entity` is being changed to make use of
the new `Identifier` type, keeping `Entity`'s API and
serialization/deserialization the same. Further changes are for
follow-up PRs.
## Solution
`Identifier` is a wrapper around `u64` split into two `u32` segments
with the idea of being generalised to not impose restrictions on
variants. That is for `Entity` to do. Instead, it is a general API for
taking bits to then merge and map into a `u64` integer. It exposes
low/high methods to return the two value portions as `u32` integers,
with then the MSB masked for usage as a type flag, enabling entity kind
discrimination and future activation/deactivation semantics.
The layout in this PR for `Identifier` is described as below, going from
MSB -> LSB.
```
|F| High value | Low value |
|_|_______________________________|________________________________|
|1| 31 | 32 |
F = Bit Flags
```
The high component in this implementation has only 31 bits, but that
still leaves 2^31 or 2,147,483,648 values that can be stored still, more
than enough for any generation/relation kinds/etc usage. The low part is
a full 32-bit index. The flags allow for 1 bit to be used for
entity/pair discrimination, as these have different usages for the
low/high portions of the `Identifier`. More bits can be reserved for
more variants or activation/deactivation purposes, but this currently
has no use in bevy.
More bits could be reserved for future features at the cost of bits for
the high component, so how much to reserve is up for discussion. Also,
naming of the struct and methods are also subject to further
bikeshedding and feedback.
Also, because IDs can have different variants, I wonder if
`Entity::from_bits` needs to return a `Result` instead of potentially
panicking on receiving an invalid ID.
PR is provided as an early WIP to obtain feedback and notes on whether
this approach is viable.
---
## Changelog
### Added
New `Identifier` struct for unifying IDs.
### Changed
`Entity` changed to use new `Identifier`/`IdentifierMask` as the
underlying ID logic.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
# Objective
This dependency is seemingly no longer used directly after #7267.
Unfortunately, this doesn't fix us having versions of `event-listener`
in our tree.
Closes#10654
## Solution
Remove it, see if anything breaks.
# Objective
- Implements change described in
https://github.com/bevyengine/bevy/issues/3022
- Goal is to allow Entity to benefit from niche optimization, especially
in the case of Option<Entity> to reduce memory overhead with structures
with empty slots
## Discussion
- First PR attempt: https://github.com/bevyengine/bevy/pull/3029
- Discord:
https://discord.com/channels/691052431525675048/1154573759752183808/1154573764240093224
## Solution
- Change `Entity::generation` from u32 to NonZeroU32 to allow for niche
optimization.
- The reason for changing generation rather than index is so that the
costs are only encountered on Entity free, instead of on Entity alloc
- There was some concern with generations being used, due to there being
some desire to introduce flags. This was more to do with the original
retirement approach, however, in reality even if generations were
reduced to 24-bits, we would still have 16 million generations available
before wrapping and current ideas indicate that we would be using closer
to 4-bits for flags.
- Additionally, another concern was the representation of relationships
where NonZeroU32 prevents us using the full address space, talking with
Joy it seems unlikely to be an issue. The majority of the time these
entity references will be low-index entries (ie. `ChildOf`, `Owes`),
these will be able to be fast lookups, and the remainder of the range
can use slower lookups to map to the address space.
- It has the additional benefit of being less visible to most users,
since generation is only ever really set through `from_bits` type
methods.
- `EntityMeta` was changed to match
- On free, generation now explicitly wraps:
- Originally, generation would panic in debug mode and wrap in release
mode due to using regular ops.
- The first attempt at this PR changed the behavior to "retire" slots
and remove them from use when generations overflowed. This change was
controversial, and likely needs a proper RFC/discussion.
- Wrapping matches current release behaviour, and should therefore be
less controversial.
- Wrapping also more easily migrates to the retirement approach, as
users likely to exhaust the exorbitant supply of generations will code
defensively against aliasing and that defensive code is less likely to
break than code assuming that generations don't wrap.
- We use some unsafe code here when wrapping generations, to avoid
branch on NonZeroU32 construction. It's guaranteed safe due to how we
perform wrapping and it results in significantly smaller ASM code.
- https://godbolt.org/z/6b6hj8PrM
## Migration
- Previous `bevy_scene` serializations have a high likelihood of being
broken, as they contain 0th generation entities.
## Current Issues
- `Entities::reserve_generations` and `EntityMapper` wrap now, even in
debug - although they technically did in release mode already so this
probably isn't a huge issue. It just depends if we need to change
anything here?
---------
Co-authored-by: Natalie Baker <natalie.baker@advancednavigation.com>
# Objective
`Column` unconditionally requires three separate allocations: one for
the data, and two for the tick Vecs. The tick Vecs aren't really needed
for Resources, so we're allocating a bunch of one-element Vecs, and it
costs two extra dereferences when fetching/inserting/removing resources.
## Solution
Drop one level lower in `ResourceData` and directly store a `BlobVec`
and two `UnsafeCell<Tick>`s. This should significantly shrink
`ResourceData` (exchanging 6 usizes for 2 u32s), removes the need to
dereference two separate ticks when inserting/removing/fetching
resources, and can significantly decrease the number of small
allocations the ECS makes by default.
This tentatively might have a non-insignificant impact on the CPU cost
for rendering since we're constantly fetching resources in draw
functions, depending on how aggressively inlined the functions are.
This requires reimplementing some of the unsafe functions that `Column`
wraps, but it also allows us to delete a few Column APIs that were only
used for Resources, so the total amount of unsafe we're maintaining
shouldn't change significantly.
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
In #9604 we removed the ability to define an `EntityCommand` as
`fn(Entity, &mut World)`. However I have since realized that `fn(Entity,
&mut World)` is an incredibly expressive and powerful way to define a
command for an entity that may or may not exist (`fn(EntityWorldMut)`
only works on entities that are alive).
## Solution
Support `EntityCommand`s in the style of `fn(Entity, &mut World)`, as
well as `fn(EntityWorldMut)`. Use a marker generic on the
`EntityCommand` trait to allow multiple impls.
The second commit in this PR replaces all of the internal command
definitions with ones using `fn` definitions. This is mostly just to
show off how expressive this style of command is -- we can revert this
commit if we'd rather avoid breaking changes.
---
## Changelog
Re-added support for expressively defining an `EntityCommand` as a
function that takes `Entity, &mut World`.
## Migration Guide
All `Command` types in `bevy_ecs`, such as `Spawn`, `SpawnBatch`,
`Insert`, etc., have been made private. Use the equivalent methods on
`Commands` or `EntityCommands` instead.
# Objective
- Make it possible to react to arbitrary state changes
- this will be useful regardless of the other changes to states
currently being discussed
## Solution
- added `StateTransitionEvent<S>` struct
- previously, this would have been impossible:
```rs
#[derive(States, Eq, PartialEq, Hash, Copy, Clone, Default)]
enum MyState {
#[default]
Foo,
Bar(MySubState),
}
enum MySubState {
Spam,
Eggs,
}
app.add_system(Update, on_enter_bar);
fn on_enter_bar(trans: EventReader<StateTransition<MyState>>){
for (befoare, after) in trans.read() {
match before, after {
MyState::Foo, MyState::Bar(_) => info!("detected transition foo => bar");
_, _ => ();
}
}
}
```
---
## Changelog
- Added
- `StateTransitionEvent<S>` - Fired on state changes of `S`
## Migration Guide
N/A no breaking changes
---------
Co-authored-by: Federico Rinaldi <gisquerin@gmail.com>
# Objective
When `BlobVec::reserve` is called with an argument causing capacity
overflow, in release build capacity overflow is ignored, and capacity is
decreased.
I'm not sure it is possible to exploit this issue using public API of
`bevy_ecs`, but better fix it anyway.
## Solution
Check for capacity overflow.
# Objective
`SystemName` might be useful in systems which accept `&mut World`.
## Solution
- `impl ExclusiveSystemParam for SystemName`
- move `SystemName` into a separate file, because it no longer belongs
to a file which defines `SystemParam`
- add a test for new impl, and for existing impl
## Changelog
- `impl ExclusiveSystemParam for SystemName`
# Objective
There are a lot of doctests that are `ignore`d for no documented reason.
And that should be fixed.
## Solution
I searched the bevy repo with the regex ` ```[a-z,]*ignore ` in order to
find all `ignore`d doctests. For each one of the `ignore`d doctests, I
did the following steps:
1. Attempt to remove the `ignored` attribute while still passing the
test. I did this by adding hidden dummy structs and imports.
2. If step 1 doesn't work, attempt to replace the `ignored` attribute
with the `no_run` attribute while still passing the test.
3. If step 2 doesn't work, keep the `ignored` attribute but add
documentation for why the `ignored` attribute was added.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
Fixes#11050
Rename ArchetypeEntity::entity to ArchetypeEntity::id to be consistent
with `EntityWorldMut`, `EntityMut` and `EntityRef`.
## Migration Guide
The method `ArchetypeEntity::entity` has been renamed to
`ArchetypeEntity::id`
# Objective
- There is an warning about non snake case on system_param.rs generated
by a macro
## Solution
- Allow non snake case on the function at fault
# Objective
Implement `ExclusiveSystemParam` for `PhantomData`.
For the same reason `SystemParam` impl exists: to simplify writing
generic code.
786abbf3f5/crates/bevy_ecs/src/system/system_param.rs (L1557)
Also for consistency.
## Solution
`impl ExclusiveSystemParam for PhantomData`.
## Changelog
Added: PhantomData<T> now implements ExclusiveSystemParam.
# Objective
Mostly for consistency.
## Solution
```rust
impl ExclusiveSystemParam for WorldId
```
- Also add a test for `SystemParam for WorldId`
## Changelog
Added: Worldd now implements ExclusiveSystemParam.
# Objective
Fix ci hang, so we can merge pr's again.
## Solution
- switch ppa action to use mesa stable versions
https://launchpad.net/~kisak/+archive/ubuntu/turtle
- use commit from #11123
---------
Co-authored-by: Stepan Koltsov <stepan.koltsov@gmail.com>
# Objective
The documentation for the `States` trait contains an error! There is a
single colon missing from `OnExit<T:Variant>`.
## Solution
Replace `OnExit<T:Variant>` with `OnExit<T::Variant>`. (Notice the added
colon.)
---
## Changelog
### Added
- Added missing colon in `States` documentation.
---
Bevy community, you may now rest easy.
# Objective
Fix#10731.
## Solution
Rename `App::add_state<T>(&mut self)` to `init_state`, and add
`App::insert_state<T>(&mut self, state: T)`. I decided on these names
because they are more similar to `init_resource` and `insert_resource`.
I also removed the `States` trait's requirement for `Default`. Instead,
`init_state` requires `FromWorld`.
---
## Changelog
- Renamed `App::add_state` to `init_state`.
- Added `App::insert_state`.
- Removed the `States` trait's requirement for `Default`.
## Migration Guide
- Renamed `App::add_state` to `init_state`.
# Objective
`Has<T>` in some niche cases may behave in an unexpected way.
Specifically, when using `Query::get` on a `Has<T>` with a despawned
entity.
## Solution
Add precision about cases wehre `Query::get` could return an `Err`.
Use `'w` for world lifetime consistently.
When implementing system params, useful to look at how other params are
implemented. `'w` makes it clear it is world, not state.
# Objective
- Allow checking if a resource has changed by its ComponentId
---
## Changelog
- Added `World::is_resource_changed_by_id()` and
`World::is_resource_added_by_id()`.
# Objective
The definition of several `QueryState` methods use unnecessary explicit
lifetimes, which adds to visual noise.
## Solution
Elide the lifetimes.
# Objective
- Users are often confused when their command effects are not visible in
the next system. This PR auto inserts sync points if there are deferred
buffers on a system and there are dependents on that system (systems
with after relationships).
- Manual sync points can lead to users adding more than needed and it's
hard for the user to have a global understanding of their system graph
to know which sync points can be merged. However we can easily calculate
which sync points can be merged automatically.
## Solution
1. Add new edge types to allow opting out of new behavior
2. Insert an sync point for each edge whose initial node has deferred
system params.
3. Reuse nodes if they're at the number of sync points away.
* add opt outs for specific edges with `after_ignore_deferred`,
`before_ignore_deferred` and `chain_ignore_deferred`. The
`auto_insert_apply_deferred` boolean on `ScheduleBuildSettings` can be
set to false to opt out for the whole schedule.
## Perf
This has a small negative effect on schedule build times.
```text
group auto-sync main-for-auto-sync
----- ----------- ------------------
build_schedule/1000_schedule 1.06 2.8±0.15s ? ?/sec 1.00 2.7±0.06s ? ?/sec
build_schedule/1000_schedule_noconstraints 1.01 26.2±0.88ms ? ?/sec 1.00 25.8±0.36ms ? ?/sec
build_schedule/100_schedule 1.02 13.1±0.33ms ? ?/sec 1.00 12.9±0.28ms ? ?/sec
build_schedule/100_schedule_noconstraints 1.08 505.3±29.30µs ? ?/sec 1.00 469.4±12.48µs ? ?/sec
build_schedule/500_schedule 1.00 485.5±6.29ms ? ?/sec 1.00 485.5±9.80ms ? ?/sec
build_schedule/500_schedule_noconstraints 1.00 6.8±0.10ms ? ?/sec 1.02 6.9±0.16ms ? ?/sec
```
---
## Changelog
- Auto insert sync points and added `after_ignore_deferred`,
`before_ignore_deferred`, `chain_no_deferred` and
`auto_insert_apply_deferred` APIs to opt out of this behavior
## Migration Guide
- `apply_deferred` points are added automatically when there is ordering
relationship with a system that has deferred parameters like `Commands`.
If you want to opt out of this you can switch from `after`, `before`,
and `chain` to the corresponding `ignore_deferred` API,
`after_ignore_deferred`, `before_ignore_deferred` or
`chain_ignore_deferred` for your system/set ordering.
- You can also set `ScheduleBuildSettings::auto_insert_sync_points` to
`false` if you want to do it for the whole schedule. Note that in this
mode you can still add `apply_deferred` points manually.
- For most manual insertions of `apply_deferred` you should remove them
as they cannot be merged with the automatically inserted points and
might reduce parallelizability of the system graph.
## TODO
- [x] remove any apply_deferred used in the engine
- [x] ~~decide if we should deprecate manually using apply_deferred.~~
We'll still allow inserting manual sync points for now for whatever edge
cases users might have.
- [x] Update migration guide
- [x] rerun schedule build benchmarks
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
- Make the implementation order consistent between all sources to fit
the order in the trait.
## Solution
- Change the implementation order.
# Objective
Since #10776 split `WorldQuery` to `WorldQueryData` and
`WorldQueryFilter`, it should be clear that the query is actually
composed of two parts. It is not factually correct to call "query" only
the data part. Therefore I suggest to rename the `Q` parameter to `D` in
`Query` and related items.
As far as I know, there shouldn't be breaking changes from renaming
generic type parameters.
## Solution
I used a combination of rust-analyzer go to reference and `Ctrl-F`ing
various patterns to catch as many cases as possible. Hopefully I got
them all. Feel free to check if you're concerned of me having missed
some.
## Notes
This and #10779 have many lines in common, so merging one will cause a
lot of merge conflicts to the other.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- The example in the docs is unsound.
Demo:
```rust
#[derive(Resource)]
struct MyRes(u32);
fn main() {
let mut w = World::new();
w.insert_resource(MyRes(0));
let (mut res, comp) = split_world_access(&mut w);
let mut r1 = res.get_resource_mut::<MyRes>().unwrap();
let mut r2 = res.get_resource_mut::<MyRes>().unwrap();
*r1 = MyRes(1);
*r2 = MyRes(2);
}
```
The API in the example allows aliasing mutable references to the same
resource. Miri also complains when running this.
## Solution
- Change the example API to make the returned `Mut` borrow from the
`OnlyResourceAccessWorld` instead of borrowing from the world via `'w`.
This prevents obtaining more than one `Mut` at the same time from it.
# Objective
The `Despawn` command breaks the hierarchy whenever you use it if the
despawned entity has a parent or any children. This is a serious footgun
because the `Despawn` command has the shortest name, the behavior is
unexpected and not likely to be what you want, and the crash that it
causes can be very difficult to track down.
## Solution
Until this can be fixed by relations, add a note mentioning the footgun
in the documentation.
## Solution
`Commands.remove` and `.retain` (because I copied `remove`s doc)
referenced `EntityWorldMut.remove` and `retain` for more detail but the
`Commands` docs are much more detailed (which makes sense because it is
the most common api), so I have instead inverted this so that
`EntityWorldMut` docs link to `Commands`.
I also made `EntityWorldMut.despawn` reference `World.despawn` for more
details, like `Commands.despawn` does.
# Objective
Test more complex function signatures for exclusive systems, and test
that `StaticSystemParam` is indeed a `SystemParam`.
I mean, it currently works, but might as well add a test for it.
# Objective
Adds `EntityCommands.retain` and `EntityWorldMut.retain` to remove all
components except the given bundle from the entity.
Fixes#10865.
## Solution
I added a private unsafe function in `EntityWorldMut` called
`remove_bundle_info` which performs the shared behaviour of `remove` and
`retain`, namely taking a `BundleInfo` of components to remove, and
removing them from the given entity. Then `retain` simply gets all the
components on the entity and filters them by whether they are in the
bundle it was passed, before passing this `BundleInfo` into
`remove_bundle_info`.
`EntityCommands.retain` just creates a new type `Retain` which runs
`EntityWorldMut.retain` when run.
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## Changelog
Added `EntityCommands.retain` and `EntityWorldMut.retain`, which remove
all components except the given bundle from the entity, they can also be
used to remove all components by passing `()` as the bundle.
