# Objective
- As stated in the related issue, this PR is to better align the feature
flag name with what it actually does and the plans for the future.
- Fixes#16852
## Solution
- Simple find / replace
## Testing
- Local run of `cargo run -p ci`
## Migration Guide
The `track_change_detection` feature flag has been renamed to
`track_location` to better reflect its extended capabilities.
# Objective
- Make working with immutable components more ergonomic
- Assist #16662
## Solution
Added `modify_component` to `World` and `EntityWorldMut`. This method
"removes" a component from an entity, gives a mutable reference to it to
a provided closure, and then "re-inserts" the component back onto the
entity. This replacement triggers the `OnReplace` and `OnInsert` hooks,
but does _not_ cause an archetype move, as the removal is purely
simulated.
## Testing
- Added doc-tests and a unit test.
---
## Showcase
```rust
use bevy_ecs::prelude::*;
/// An immutable component.
#[derive(Component, PartialEq, Eq, Debug)]
#[component(immutable)]
struct Foo(bool);
let mut world = World::default();
let mut entity = world.spawn(Foo(false));
assert_eq!(entity.get::<Foo>(), Some(&Foo(false)));
// Before the closure is executed, the `OnReplace` hooks/observers are triggered
entity.modify_component(|foo: &mut Foo| {
foo.0 = true;
});
// After the closure is executed, `OnInsert` hooks/observers are triggered
assert_eq!(entity.get::<Foo>(), Some(&Foo(true)));
```
## Notes
- If the component is not available on the entity, the closure and hooks
aren't executed, and `None` is returned. I chose this as an alternative
to returning an error or panicking, but I'm open to changing that based
on feedback.
- This relies on `unsafe`, in particular for accessing the `Archetype`
to trigger hooks. All the unsafe operations are contained within
`DeferredWorld::modify_component`, and I would appreciate that this
function is given special attention to ensure soundness.
- The `OnAdd` hook can never be triggered by this method, since the
component must already be inserted. I have chosen to not trigger
`OnRemove`, as I believe it makes sense that this method is purely a
replacement operation, not an actual removal/insertion.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Malek <50841145+MalekiRe@users.noreply.github.com>
# Objective
`EntityMutExcept` can currently be cloned, which can easily violate
aliasing rules.
## Solution
- Remove the `Clone` impl for `EntityMutExcept`
- Also manually derived `Clone` impl for `EntityRefExcept` so that `B:
Clone` isn't required, and also impl'd `Copy`
## Testing
Compile failure tests would be good for this, but I'm not exactly sure
how to set that up.
## Migration Guide
- `EntityMutExcept` can no-longer be cloned, as this violates Rust's
memory safety rules.
## Objective
Commands were previously limited to structs that implemented `Command`.
Now there are blanket implementations for closures, which (in my
opinion) are generally preferable.
Internal commands within `commands/mod.rs` have been switched from
structs to closures, but there are a number of internal commands in
other areas of the engine that still use structs. I'd like to tidy these
up by moving their implementations to methods on
`World`/`EntityWorldMut` and changing `Commands` to use those methods
through closures.
This PR handles the following:
- `TriggerEvent` and `EmitDynamicTrigger` double as commands and helper
structs, and can just be moved to `World` methods.
- Four structs that enabled insertion/removal of components via
reflection. This functionality shouldn't be exclusive to commands, and
can be added to `EntityWorldMut`.
- Five structs that mostly just wrapped `World` methods, and can be
replaced with closures that do the same thing.
## Solution
- __Observer Triggers__ (`observer/trigger_event.rs` and
`observer/mod.rs`)
- Moved the internals of `TriggerEvent` to the `World` methods that used
it.
- Replaced `EmitDynamicTrigger` with two `World` methods:
- `trigger_targets_dynamic`
- `trigger_targets_dynamic_ref`
- `TriggerTargets` was now the only thing in
`observer/trigger_event.rs`, so it's been moved to `observer/mod.rs` and
`trigger_event.rs` was deleted.
- __Reflection Insert/Remove__ (`reflect/entity_commands.rs`)
- Replaced the following `Command` impls with equivalent methods on
`EntityWorldMut`:
- `InsertReflect` -> `insert_reflect`
- `InsertReflectWithRegistry` -> `insert_reflect_with_registry`
- `RemoveReflect` -> `remove_reflect`
- `RemoveReflectWithRegistry` -> `remove_reflect_with_registry`
- __System Registration__ (`system/system_registry.rs`)
- The following `Command` impls just wrapped a `World` method and have
been replaced with closures:
- `RunSystemWith`
- `UnregisterSystem`
- `RunSystemCachedWith`
- `UnregisterSystemCached`
- `RegisterSystem` called a helper function that basically worked as a
constructor for `RegisteredSystem` and made sure it came with a marker
component. That helper function has been replaced with
`RegisteredSystem::new` and a `#[require]`.
## Possible Addition
The extension trait that adds the reflection commands,
`ReflectCommandExt`, isn't strictly necessary; we could just `impl
EntityCommands`. We could even move them to the same files as the main
impls and put it behind a `#[cfg]`.
The PR that added it [had a similar
conversation](https://github.com/bevyengine/bevy/pull/8895#discussion_r1234713671)
and decided to stick with the trait, but we could revisit it here if so
desired.
# Objective
Fixes#16104
## Solution
I removed all instances of `:?` and put them back one by one where it
caused an error.
I removed some bevy_utils helper functions that were only used in 2
places and don't add value. See: #11478
## Testing
CI should catch the mistakes
## Migration Guide
`bevy::utils::{dbg,info,warn,error}` were removed. Use
`bevy::utils::tracing::{debug,info,warn,error}` instead.
---------
Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
# Objective
Some types like `RenderEntity` and `MainEntity` are just wrappers around
`Entity`, so they should be able to implement
`EntityBorrow`/`TrustedEntityBorrow`. This allows using them with
`EntitySet` functionality.
The `EntityRef` family are more than direct wrappers around `Entity`,
but can still benefit from being unique in a collection.
## Solution
Implement `EntityBorrow` and `TrustedEntityBorrow` for simple `Entity`
newtypes and `EntityRef` types.
These impls are an explicit decision to have the `EntityRef` types
compare like just `Entity`.
`EntityWorldMut` is omitted from this impl, because it explicitly
contains a `&mut World` as well, and we do not ever use more than one at
a time.
Add `EntityBorrow` to the `bevy_ecs` prelude.
## Migration Guide
`NormalizedWindowRef::entity` has been replaced with an
`EntityBorrow::entity` impl.
# Objective
`EntityHashMap` and `EntityHashSet` iterators do not implement
`EntitySetIterator`.
## Solution
Make them newtypes instead of aliases. The methods that create the
iterators can then produce their own newtypes that carry the `Hasher`
generic and implement `EntitySetIterator`. Functionality remains the
same otherwise.
There are some other small benefits, f.e. the removal of `with_hasher`
associated functions, and the ability to implement more traits
ourselves.
`MainEntityHashMap` and `MainEntityHashSet` are currently left as the
previous type aliases, because supporting general `TrustedEntityBorrow`
hashing is more complex. However, it can also be done.
## Testing
Pre-existing `EntityHashMap` tests.
## Migration Guide
Users of `with_hasher` and `with_capacity_and_hasher` on
`EntityHashMap`/`Set` must now use `new` and `with_capacity`
respectively.
If the non-newtyped versions are required, they can be obtained via
`Deref`, `DerefMut` or `into_inner` calls.
# Objective
#16132 introduced entity cloning functionality, and while it works and
is useful, it can be made faster. This is the promised follow-up to
improve performance.
## Solution
**PREFACE**: This is my first time writing `unsafe` in rust and I have
only vague idea about what I'm doing. I would encourage reviewers to
scrutinize `unsafe` parts in particular.
The solution is to clone component data to an intermediate buffer and
use `EntityWorldMut::insert_by_ids` to insert components without
additional archetype moves.
To facilitate this, `EntityCloner::clone_entity` now reads all
components of the source entity and provides clone handlers with the
ability to read component data straight from component storage using
`read_source_component` and write to an intermediate buffer using
`write_target_component`. `ComponentId` is used to check that requested
type corresponds to the type available on source entity.
Reflect-based handler is a little trickier to pull of: we only have
`&dyn Reflect` and no direct access to the underlying data.
`ReflectFromPtr` can be used to get `&dyn Reflect` from concrete
component data, but to write it we need to create a clone of the
underlying data using `Reflect`. For this reason only components that
have `ReflectDefault` or `ReflectFromReflect` or `ReflectFromWorld` can
be cloned, all other components will be skipped. The good news is that
this is actually only a temporary limitation: once #13432 lands we will
be able to clone component without requiring one of these `type data`s.
This PR also introduces `entity_cloning` benchmark to better compare
changes between the PR and main, you can see the results in the
**showcase** section.
## Testing
- All previous tests passing
- Added test for fast reflect clone path (temporary, will be removed
after reflection-based cloning lands)
- Ran miri
## Showcase
Here's a table demonstrating the improvement:
| **benchmark** | **main, avg** | **PR, avg** | **change, avg** |
| ----------------------- | ------------- | ----------- |
--------------- |
| many components reflect | 18.505 µs | 2.1351 µs | -89.095% |
| hierarchy wide reflect* | 22.778 ms | 4.1875 ms | -81.616% |
| hierarchy tall reflect* | 107.24 µs | 26.322 µs | -77.141% |
| hierarchy many reflect | 78.533 ms | 9.7415 ms | -87.596% |
| many components clone | 1.3633 µs | 758.17 ns | -45.937% |
| hierarchy wide clone* | 2.7716 ms | 3.3411 ms | +20.546% |
| hierarchy tall clone* | 17.646 µs | 20.190 µs | +17.379% |
| hierarchy many clone | 5.8779 ms | 4.2650 ms | -27.439% |
*: these benchmarks have entities with only 1 component
## Considerations
Once #10154 is resolved a large part of the functionality in this PR
will probably become obsolete. It might still be a little bit faster
than using command batching, but the complexity might not be worth it.
## Migration Guide
- `&EntityCloner` in component clone handlers is changed to `&mut
ComponentCloneCtx` to better separate data.
- Changed `EntityCloneHandler` from enum to struct and added convenience
functions to add default clone and reflect handler more easily.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
# Objective
In current Bevy, it is very inconvenient to mutably retrieve a
user-provided list of entities more than one element at a time.
If the list contains any duplicate entities, we risk mutable aliasing.
Users of `Query::iter_many_mut` do not have access to `Iterator` trait,
and thus miss out on common functionality, for instance collecting their
`QueryManyIter`.
We can circumvent this issue with validation, however that entails
checking every entity against all others for inequality, or utilizing an
`EntityHashSet`. Even if an entity list remains unchanged, this
validation is/would have to be redone every time we wish to fetch with
the list.
This presents a lot of wasted work, as we often trivially know an entity
list to be unique f.e.: `QueryIter` will fetch every `Entity` once and
only once.
As more things become entities – assets, components, queries – this
issue will become more pronounced.
`get_many`/`many`/`iter_many`/`par_iter_many`-like functionality is all
affected.
## Solution
The solution this PR proposes is to introduce functionality built around
a new trait: `EntitySet`.
The goal is to preserve the property of "uniqueness" in a list wherever
possible, and then rely on it as a bound within new `*_many_unique`
methods to avoid the need for validation.
This is achieved using `Iterator`:
`EntitySet` is blanket implemented for any `T` that implements
`IntoIterator<IntoIter: EntitySetIterator>`.
`EntitySetIterator` is the unsafe trait that actually guarantees an
iterator to be "unique" via its safety contract.
We define an "Iterator over unique entities" as: "No two entities
returned by the iterator may compare equal."
For iterators that cannot return more than 1 element, this is trivially
true.
Whether an iterator can satisfy this is up to the `EntitySetIterator`
implementor to ensure, hence the unsafe.
However, this is not yet a complete solution. Looking at the signature
of `iter_many`, we find that `IntoIterator::Item` is not `Entity`, but
is instead bounded by the `Borrow<Entity>` trait. That is because
iteration without consuming the collection will often yield us
references, not owned items.
`Borrow<Entity>` presents an issue: The `Borrow` docs state that `x = y`
should equal `x.borrow() = y.borrow()`, but unsafe cannot rely on this
for soundness. We run into similar problems with other trait
implementations of any `Borrow<Entity>` type: `PartialEq`, `Eq`,
`PartialOrd`, `Ord`, `Hash`, `Clone`, `Borrow`, and `BorrowMut`.
This PR solves this with the unsafe `TrustedEntityBorrow` trait:
Any implementor promises that the behavior of the aforementioned traits
matches that of the underlying entity.
While `Borrow<Entity>` was the inspiration, we use our own counterpart
trait `EntityBorrow` as the supertrait to `TrustedEntityBorrow`, so we
can circumvent the limitations of the existing `Borrow<T>` blanket
impls.
All together, these traits allow us to implement `*_many_unique`
functionality with a lone `EntitySet` bound.
`EntitySetIterator` is implemented for all the std iterators and
iterator adapters that guarantee or preserve uniqueness, so we can
filter, skip, take, step, reverse, ... our unique entity iterators
without worry!
Sadly, current `HashSet` iterators do not carry the necessary type
information with them to determine whether the source `HashSet` produces
logic errors; A malicious `Hasher` could compromise a `HashSet`.
`HashSet` iteration is generally discouraged in the first place, so we
also exclude the set operation iterators, even though they do carry the
`Hasher` type parameter.
`BTreeSet` implements `EntitySet` without any problems.
If an iterator type cannot guarantee uniqueness at compile time, then a
user can still attach `EntitySetIterator` to an individual instance of
that type via `UniqueEntityIter::from_iterator_unchecked`.
With this, custom types can use `UniqueEntityIter<I>` as their
`IntoIterator::IntoIter` type, if necessary.
This PR is focused on the base concept, and expansions on it are left
for follow-up PRs. See "Potential Future Work" below.
## Testing
Doctests on `iter_many_unique`/`iter_many_unique_mut` + 2 tests in
entity_set.rs.
## Showcase
```rust
// Before:
fn system(player_list: Res<SomeUniquePlayerList>, players: Query<&mut Player>) {
let value = 0;
while let Some(player) = players.iter_many_mut(player_list).fetch_next() {
value += mem::take(player.value_mut())
}
}
// After:
fn system(player_list: Res<SomeUniquePlayerList>, players: Query<&mut Player>) {
let value = players
.iter_many_unique_mut(player_list)
.map(|player| mem::take(player.value_mut()))
.sum();
}
```
## Changelog
- added `EntityBorrow`, `TrustedEntityBorrow`, `EntitySet` and
`EntitySetIterator` traits
- added `iter_many_unique`, `iter_many_unique_mut`,
`iter_many_unique_unsafe` methods on `Query`
- added `iter_many_unique`, `iter_many_unique_mut`,
`iter_many_unique_manual` and `iter_many_unique_unchecked_manual`
methods on `QueryState`
- added corresponding `QueryManyUniqueIter`
- added `UniqueEntityIter`
## Migration Guide
Any custom type used as a `Borrow<Entity>` entity list item for an
`iter_many` method now has to implement `EntityBorrow` instead. Any type
that implements `Borrow<Entity>` can trivially implement `EntityBorrow`.
## Potential Future Work
- `ToEntitySet` trait for converting any entity iterator into an
`EntitySetIterator`
- `EntityIndexSet/Map` to tie in hashing with `EntitySet`
- add `EntityIndexSetSlice/MapSlice`
- requires: `EntityIndexSet/Map`
- Implementing `par_iter_many_unique_mut` for parallel mutable iteration
- requires: `par_iter_many`
- allow collecting into `UniqueEntityVec` to store entity sets
- add `UniqueEntitySlice`s
- Doesn't require, but should be done after: `UniqueEntityVec`
- add `UniqueEntityArray`s
- Doesn't require, but should be done after: `UniqueEntitySlice`
- `get_many_unique`/`many_unique` methods
- requires: `UniqueEntityArray`
- `World::entity_unique` to match `World::entity` methods
- Doesn't require, but makes sense after:
`get_many_unique`/`many_unique`
- implement `TrustedEntityBorrow` for the `EntityRef` family
- Doesn't require, but makes sense after: `UniqueEntityVec`
# Objective
- Contributes to #15460
## Solution
- Added the following features:
- `std` (default)
- `async_executor` (default)
- `edge_executor`
- `critical-section`
- `portable-atomic`
- Gated `tracing` in `bevy_utils` to allow compilation on certain
platforms
- Switched from `tracing` to `log` for simple message logging within
`bevy_ecs`. Note that `tracing` supports capturing from `log` so this
should be an uncontroversial change.
- Fixed imports and added feature gates as required
- Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only
needed for parallel operations which are already gated behind
`multi_threaded` anyway.
## Testing
- Added to `compile-check-no-std` CI command
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section,portable-atomic --target
thumbv6m-none-eabi`
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section`
- `cargo check -p bevy_ecs --no-default-features`
## Draft Release Notes
Bevy's core ECS now supports `no_std` platforms.
In prior versions of Bevy, it was not possible to work with embedded or
niche platforms due to our reliance on the standard library, `std`. This
has blocked a number of novel use-cases for Bevy, such as an embedded
database for IoT devices, or for creating games on retro consoles.
With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a
`no_std` platform, you must disable default features and enable the new
`edge_executor` and `critical-section` features. You may also need to
enable `portable-atomic` and `critical-section` if your platform does
not natively support all atomic types and operations used by Bevy.
```toml
[dependencies]
bevy_ecs = { version = "0.16", default-features = false, features = [
# Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico)
"portable-atomic",
"critical-section",
# Optional
"bevy_reflect",
"serialize",
"bevy_debug_stepping",
"edge_executor"
] }
```
Currently, this has been tested on bare-metal x86 and the Raspberry Pi
Pico. If you have trouble using `bevy_ecs` on a particular platform,
please reach out either through a GitHub issue or in the `no_std`
working group on the Bevy Discord server.
Keep an eye out for future `no_std` updates as we continue to improve
the parity between `std` and `no_std`. We look forward to seeing what
kinds of applications are now possible with Bevy!
## Notes
- Creating PR in draft to ensure CI is passing before requesting
reviews.
- This implementation has no support for multithreading in `no_std`,
especially due to `NonSend` being unsound if allowed in multithreading.
The reason is we cannot check the `ThreadId` in `no_std`, so we have no
mechanism to at-runtime determine if access is sound.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com>
# Objective
- Cleanup deprecated code
## Solution
- Removed `#[deprecated]` items which were marked as such in 0.15 or
prior versions.
## Migration Guide
- The following deprecated items were removed: `Events::get_reader`,
`Events::get_reader_current`, `ManualEventReader`,
`Condition::and_then`, `Condition::or_else`, `World::,many_entities`,
`World::many_entities_mut`, `World::get_many_entities`,
`World::get_many_entities_dynamic`, `World::get_many_entities_mut`,
`World::get_many_entities_dynamic_mut`,
`World::get_many_entities_from_set_mut`
# Objective
Expand `track_change_detection` feature to also track entity spawns and
despawns. Use this to create better error messages.
# Solution
Adds `Entities::entity_get_spawned_or_despawned_by` as well as `{all
entity reference types}::spawned_by`.
This also removes the deprecated `get_many_entities_mut` & co (and
therefore can't land in 0.15) because we don't yet have no Polonius.
## Testing
Added a test that checks that the locations get updated and these
updates are ordered correctly vs hooks & observers.
---
## Showcase
Access location:
```rust
let mut world = World::new();
let entity = world.spawn_empty().id();
println!("spawned by: {}", world.entity(entity).spawned_by());
```
```
spawned by: src/main.rs:5:24
```
Error message (with `track_change_detection`):
```rust
world.despawn(entity);
world.entity(entity);
```
```
thread 'main' panicked at src/main.rs:11:11:
Entity 0v1#4294967296 was despawned by src/main.rs:10:11
```
and without:
```
thread 'main' panicked at src/main.rs:11:11:
Entity 0v1#4294967296 does not exist (enable `track_change_detection` feature for more details)
```
Similar error messages now also exists for `Query::get`,
`World::entity_mut`, `EntityCommands` creation and everything that
causes `B0003`, e.g.
```
error[B0003]: Could not insert a bundle (of type `MaterialMeshBundle<StandardMaterial>`) for entity Entity { index: 7, generation: 1 }, which was despawned by src/main.rs:10:11. See: https://bevyengine.org/learn/errors/#b0003
```
---------
Co-authored-by: kurk070ff <108901106+kurk070ff@users.noreply.github.com>
Co-authored-by: Freya Pines <freya@MacBookAir.lan>
Co-authored-by: Freya Pines <freya@Freyas-MacBook-Air.local>
Co-authored-by: Matty Weatherley <weatherleymatthew@gmail.com>
## Objective
Thanks to @eugineerd's work on entity cloning (#16132), we now have a
robust way to copy components between entities. We can extend this to
implement some useful functionality that would have been more
complicated before.
Closes#15350.
## Solution
`EntityCloneBuilder` now automatically includes required components
alongside any component added/removed from the component filter.
Added the following methods to `EntityCloneBuilder`:
- `move_components`
- `without_required_components`
Added the following methods to `EntityWorldMut` and `EntityCommands`:
- `clone_with`
- `clone_components`
- `move_components`
Also added `clone_and_spawn` and `clone_and_spawn_with` to
`EntityWorldMut` (`EntityCommands` already had them).
## Showcase
```
assert_eq!(world.entity(entity_a).get::<B>(), Some(&B));
assert_eq!(world.entity(entity_b).get::<B>(), None);
world.entity_mut(entity_a).clone_components::<B>(entity_b);
assert_eq!(world.entity(entity_a).get::<B>(), Some(&B));
assert_eq!(world.entity(entity_b).get::<B>(), Some(&B));
assert_eq!(world.entity(entity_a).get::<C>(), Some(&C(5)));
assert_eq!(world.entity(entity_b).get::<C>(), None);
world.entity_mut(entity_a).move_components::<C>(entity_b);
assert_eq!(world.entity(entity_a).get::<C>(), None);
assert_eq!(world.entity(entity_b).get::<C>(), Some(&C(5)));
```
## Objective
Some structs and methods in the ECS internals have names that don't
describe their purpose very well, and sometimes don't have docs either.
Also, the function `remove_bundle_from_archetype` is a counterpart to
`BundleInfo::add_bundle_to_archetype`, but isn't a method and is in a
different file.
## Solution
- Renamed the following structs and added docs:
| Before | After |
|----------------------|------------------------------|
| `AddBundle` | `ArchetypeAfterBundleInsert` |
| `InsertBundleResult` | `ArchetypeMoveType` |
- Renamed the following methods:
| Before | After |
|---------------------------------------|----------------------------------------------|
| `Edges::get_add_bundle` | `Edges::get_archetype_after_bundle_insert` |
| `Edges::insert_add_bundle` |
`Edges::cache_archetype_after_bundle_insert` |
| `Edges::get_remove_bundle` |
`Edges::get_archetype_after_bundle_remove` |
| `Edges::insert_remove_bundle` |
`Edges::cache_archetype_after_bundle_remove` |
| `Edges::get_take_bundle` | `Edges::get_archetype_after_bundle_take` |
| `Edges::insert_take_bundle` |
`Edges::cache_archetype_after_bundle_take` |
- Moved `remove_bundle_from_archetype` from `world/entity_ref.rs` to
`BundleInfo`. I left the function in entity_ref in the first commit for
comparison, look there for the diff of comments and whatnot.
- Tidied up docs:
- General grammar and spacing.
- Made the usage of "insert" and "add" more consistent.
- Removed references to information that isn't there.
- Renamed `BundleInfo::add_bundle_to_archetype` to
`BundleInfo::insert_bundle_into_archetype` for consistency.
Updating dependencies; adopted version of #15696. (Supercedes #15696.)
Long answer: hashbrown is no longer using ahash by default, meaning that
we can't use the default-hasher methods with ahasher. So, we have to use
the longer-winded versions instead. This takes the opportunity to also
switch our default hasher as well, but without actually enabling the
default-hasher feature for hashbrown, meaning that we'll be able to
change our hasher more easily at the cost of all of these method calls
being obnoxious forever.
One large change from 0.15 is that `insert_unique_unchecked` is now
`unsafe`, and for cases where unsafe code was denied at the crate level,
I replaced it with `insert`.
## Migration Guide
`bevy_utils` has updated its version of `hashbrown` to 0.15 and now
defaults to `foldhash` instead of `ahash`. This means that if you've
hard-coded your hasher to `bevy_utils::AHasher` or separately used the
`ahash` crate in your code, you may need to switch to `foldhash` to
ensure that everything works like it does in Bevy.
# Objective
- A `Trigger` has multiple associated `Entity`s - the entity observing
the event, and the entity that was targeted by the event.
- The field `entity: Entity` encodes no semantic information about what
the entity is used for, you can already tell that it's an `Entity` by
the type signature!
## Solution
- Rename `trigger.entity()` to `trigger.target()`
---
## Changelog
- `Trigger`s are associated with multiple entities. `Trigger::entity()`
has been renamed to `Trigger::target()` to reflect the semantics of the
entity being returned.
## Migration Guide
- Rename `Trigger::entity()` to `Trigger::target()`.
- Rename `ObserverTrigger::entity` to `ObserverTrigger::target`
# Objective
Fixes#16706
## Solution
- Added new method: `try_resource_scope` which returns `None` if the
requested resource doesn't exist.
- Changed the `resource_scope` test to use `try_resource_scope` as well
to test for the `None` case.
---
## Showcase
```rust
world.try_resource_scope::<MyResource, _>(|world, mut my_resource| {
// do something with the resource if it exists
});
```
# Objective
Fixes typos in bevy project, following suggestion in
https://github.com/bevyengine/bevy-website/pull/1912#pullrequestreview-2483499337
## Solution
I used https://github.com/crate-ci/typos to find them.
I included only the ones that feel undebatable too me, but I am not in
game engine so maybe some terms are expected.
I left out the following typos:
- `reparametrize` => `reparameterize`: There are a lot of occurences, I
believe this was expected
- `semicircles` => `hemicircles`: 2 occurences, may mean something
specific in geometry
- `invertation` => `inversion`: may mean something specific
- `unparented` => `parentless`: may mean something specific
- `metalness` => `metallicity`: may mean something specific
## Testing
- Did you test these changes? If so, how? I did not test the changes,
most changes are related to raw text. I expect the others to be tested
by the CI.
- Are there any parts that need more testing? I do not think
- How can other people (reviewers) test your changes? Is there anything
specific they need to know? To me there is nothing to test
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
---
## Migration Guide
> This section is optional. If there are no breaking changes, you can
delete this section.
(kept in case I include the `reparameterize` change here)
- If this PR is a breaking change (relative to the last release of
Bevy), describe how a user might need to migrate their code to support
these changes
- Simply adding new functionality is not a breaking change.
- Fixing behavior that was definitely a bug, rather than a questionable
design choice is not a breaking change.
## Questions
- [x] Should I include the above typos? No
(https://github.com/bevyengine/bevy/pull/16702#issuecomment-2525271152)
- [ ] Should I add `typos` to the CI? (I will check how to configure it
properly)
This project looks awesome, I really enjoy reading the progress made,
thanks to everyone involved.
# Objective
- Remove `derive_more`'s error derivation and replace it with
`thiserror`
## Solution
- Added `derive_more`'s `error` feature to `deny.toml` to prevent it
sneaking back in.
- Reverted to `thiserror` error derivation
## Notes
Merge conflicts were too numerous to revert the individual changes, so
this reversion was done manually. Please scrutinise carefully during
review.
# Objective
- Fixes#16498
## Solution
- Trivially swaps ordering of hooks and observers for all call sites
where they are triggered for `on_replace` or `on_remove`
## Testing
- Just CI
---
## Migration Guide
The order of hooks and observers for `on_replace` and `on_remove` has
been swapped. Observers are now run before hooks. This is a more natural
ordering where the removal ordering is inverted compared to the
insertion ordering.
# Objective
On the web, it's common to attach observers to windows. As @viridia has
discovered, this can be quite a nice paradigm in bevy as well when
applied to observers. The changes here are intended to make this
possible.
+ Adds a new default picking back-end as part to the core picking plugin
(which can be disabled) that causes pointers on windows to treat the
window entity as the final hit, behind everything else. This means
clicking empty space now dispatches normal picking events to the window,
and is especially nice for drag-and-drop functionality.
+ Adds a new traversal type, specific to picking events, that causes
them to bubble up to the window entity after they reach the root of the
hierarchy.
## Solution
The window picking back-end is extremely simple, but the bubbling
changes are much more complex, since they require doing a different
traversal depending on the picking event.
To achieve this, `Traversal` has been made generic over an associated
sized data type `D`. Observer bounds have been changed such that
`Event::Traversal<D>` is required for `Trigger<D>`. A blanket
implementation has been added for `()` and `Parent` that preserves the
existing functionality. A new `PointerTraversal` traversal has been
implemented, with a blanket implementation for `Traversal<Pointer<E>>`.
It is still possible to use `Parent` as the traversal for any event,
because of the blanket implementation. It is now possible for users to
add other custom traversals, which read event data during traversal.
## Testing
I tested these changes locally on some picking UI prototypes I have been
playing with. I also tested them on the picking examples.
---------
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
# Objective
- Currently adding observers spawns an entity which implicitly flushes
the command queue, which can cause undefined behaviour if the
`WorldEntityMut` is used after this
- The reason `WorldEntityMut` attempted to (unsuccessfully) avoid
flushing commands until finished was that such commands may move or
despawn the entity being referenced, invalidating the cached location.
- With the introduction of hooks and observers, this isn't sensible
anymore as running the commands generated by hooks immediately is
required to maintain correct ordering of operations and to not expose
the world in an inconsistent state
- Objective is to make command flushing deterministic and fix the
related issues
- Fixes#16212
- Fixes#14621
- Fixes#16034
## Solution
- Allow `WorldEntityMut` to exist even when it refers to a despawned
entity by allowing `EntityLocation` to be marked invalid
- Add checks to all methods to panic if trying to access a despawned
entity
- Flush command queue after every operation that might trigger hooks or
observers
- Update entity location always after flushing command queue
## Testing
- Added test cases for currently broken behaviour
- Added test cases that flushes happen in all operations
- Added test cases to ensure hooks and commands are run exactly in
correct order when nested
---
Todo:
- [x] Write migration guide
- [x] Add tests that using `EntityWorldMut` on a despawned entity panics
- [x] Add tests that commands are flushed after every operation that is
supposed to flush them
- [x] Add tests that hooks, observers and their spawned commands are run
in the correct order when nested
---
## Migration Guide
Previously `EntityWorldMut` triggered command queue flushes in
unpredictable places, which could interfere with hooks and observers.
Now the command queue is flushed always immediately after any call in
`EntityWorldMut` that spawns or despawns an entity, or adds, removes or
replaces a component. This means hooks and observers will run their
commands in the correct order.
As a side effect, there is a possibility that a hook or observer could
despawn the entity that is being referred to by `EntityWorldMut`. This
could already currently happen if an observer was added while keeping an
`EntityWorldMut` referece and would cause unsound behaviour. If the
entity has been despawned, calling any methods which require the entity
location will panic. This matches the behaviour that `Commands` will
panic if called on an already despawned entity. In the extremely rare
case where taking a new `EntityWorldMut` reference or otherwise
restructuring the code so that this case does not happen is not
possible, there's a new `is_despawned` method that can be used to check
if the referred entity has been despawned.
# Objective
- Fixes#16208
## Solution
- Added an associated type to `Component`, `Mutability`, which flags
whether a component is mutable, or immutable. If `Mutability= Mutable`,
the component is mutable. If `Mutability= Immutable`, the component is
immutable.
- Updated `derive_component` to default to mutable unless an
`#[component(immutable)]` attribute is added.
- Updated `ReflectComponent` to check if a component is mutable and, if
not, panic when attempting to mutate.
## Testing
- CI
- `immutable_components` example.
---
## Showcase
Users can now mark a component as `#[component(immutable)]` to prevent
safe mutation of a component while it is attached to an entity:
```rust
#[derive(Component)]
#[component(immutable)]
struct Foo {
// ...
}
```
This prevents creating an exclusive reference to the component while it
is attached to an entity. This is particularly powerful when combined
with component hooks, as you can now fully track a component's value,
ensuring whatever invariants you desire are upheld. Before this would be
done my making a component private, and manually creating a `QueryData`
implementation which only permitted read access.
<details>
<summary>Using immutable components as an index</summary>
```rust
/// This is an example of a component like [`Name`](bevy::prelude::Name), but immutable.
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Component)]
#[component(
immutable,
on_insert = on_insert_name,
on_replace = on_replace_name,
)]
pub struct Name(pub &'static str);
/// This index allows for O(1) lookups of an [`Entity`] by its [`Name`].
#[derive(Resource, Default)]
struct NameIndex {
name_to_entity: HashMap<Name, Entity>,
}
impl NameIndex {
fn get_entity(&self, name: &'static str) -> Option<Entity> {
self.name_to_entity.get(&Name(name)).copied()
}
}
fn on_insert_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) {
let Some(&name) = world.entity(entity).get::<Name>() else {
unreachable!()
};
let Some(mut index) = world.get_resource_mut::<NameIndex>() else {
return;
};
index.name_to_entity.insert(name, entity);
}
fn on_replace_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) {
let Some(&name) = world.entity(entity).get::<Name>() else {
unreachable!()
};
let Some(mut index) = world.get_resource_mut::<NameIndex>() else {
return;
};
index.name_to_entity.remove(&name);
}
// Setup our name index
world.init_resource::<NameIndex>();
// Spawn some entities!
let alyssa = world.spawn(Name("Alyssa")).id();
let javier = world.spawn(Name("Javier")).id();
// Check our index
let index = world.resource::<NameIndex>();
assert_eq!(index.get_entity("Alyssa"), Some(alyssa));
assert_eq!(index.get_entity("Javier"), Some(javier));
// Changing the name of an entity is also fully capture by our index
world.entity_mut(javier).insert(Name("Steven"));
// Javier changed their name to Steven
let steven = javier;
// Check our index
let index = world.resource::<NameIndex>();
assert_eq!(index.get_entity("Javier"), None);
assert_eq!(index.get_entity("Steven"), Some(steven));
```
</details>
Additionally, users can use `Component<Mutability = ...>` in trait
bounds to enforce that a component _is_ mutable or _is_ immutable. When
using `Component` as a trait bound without specifying `Mutability`, any
component is applicable. However, methods which only work on mutable or
immutable components are unavailable, since the compiler must be
pessimistic about the type.
## Migration Guide
- When implementing `Component` manually, you must now provide a type
for `Mutability`. The type `Mutable` provides equivalent behaviour to
earlier versions of `Component`:
```rust
impl Component for Foo {
type Mutability = Mutable;
// ...
}
```
- When working with generic components, you may need to specify that
your generic parameter implements `Component<Mutability = Mutable>`
rather than `Component` if you require mutable access to said component.
- The entity entry API has had to have some changes made to minimise
friction when working with immutable components. Methods which
previously returned a `Mut<T>` will now typically return an
`OccupiedEntry<T>` instead, requiring you to add an `into_mut()` to get
the `Mut<T>` item again.
## Draft Release Notes
Components can now be made immutable while stored within the ECS.
Components are the fundamental unit of data within an ECS, and Bevy
provides a number of ways to work with them that align with Rust's rules
around ownership and borrowing. One part of this is hooks, which allow
for defining custom behavior at key points in a component's lifecycle,
such as addition and removal. However, there is currently no way to
respond to _mutation_ of a component using hooks. The reasons for this
are quite technical, but to summarize, their addition poses a
significant challenge to Bevy's core promises around performance.
Without mutation hooks, it's relatively trivial to modify a component in
such a way that breaks invariants it intends to uphold. For example, you
can use `core::mem::swap` to swap the components of two entities,
bypassing the insertion and removal hooks.
This means the only way to react to this modification is via change
detection in a system, which then begs the question of what happens
_between_ that alteration and the next run of that system?
Alternatively, you could make your component private to prevent
mutation, but now you need to provide commands and a custom `QueryData`
implementation to allow users to interact with your component at all.
Immutable components solve this problem by preventing the creation of an
exclusive reference to the component entirely. Without an exclusive
reference, the only way to modify an immutable component is via removal
or replacement, which is fully captured by component hooks. To make a
component immutable, simply add `#[component(immutable)]`:
```rust
#[derive(Component)]
#[component(immutable)]
struct Foo {
// ...
}
```
When implementing `Component` manually, there is an associated type
`Mutability` which controls this behavior:
```rust
impl Component for Foo {
type Mutability = Mutable;
// ...
}
```
Note that this means when working with generic components, you may need
to specify that a component is mutable to gain access to certain
methods:
```rust
// Before
fn bar<C: Component>() {
// ...
}
// After
fn bar<C: Component<Mutability = Mutable>>() {
// ...
}
```
With this new tool, creating index components, or caching data on an
entity should be more user friendly, allowing libraries to provide APIs
relying on components and hooks to uphold their invariants.
## Notes
- ~~I've done my best to implement this feature, but I'm not happy with
how reflection has turned out. If any reflection SMEs know a way to
improve this situation I'd greatly appreciate it.~~ There is an
outstanding issue around the fallibility of mutable methods on
`ReflectComponent`, but the DX is largely unchanged from `main` now.
- I've attempted to prevent all safe mutable access to a component that
does not implement `Component<Mutability = Mutable>`, but there may
still be some methods I have missed. Please indicate so and I will
address them, as they are bugs.
- Unsafe is an escape hatch I am _not_ attempting to prevent. Whatever
you do with unsafe is between you and your compiler.
- I am marking this PR as ready, but I suspect it will undergo fairly
major revisions based on SME feedback.
- I've marked this PR as _Uncontroversial_ based on the feature, not the
implementation.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
Co-authored-by: Nuutti Kotivuori <naked@iki.fi>
## Objective
Fixes#1515
This PR implements a flexible entity cloning system. The primary use
case for it is to clone dynamically-generated entities.
Example:
```rs
#[derive(Component, Clone)]
pub struct Projectile;
#[derive(Component, Clone)]
pub struct Damage {
value: f32,
}
fn player_input(
mut commands: Commands,
projectiles: Query<Entity, With<Projectile>>,
input: Res<ButtonInput<KeyCode>>,
) {
// Fire a projectile
if input.just_pressed(KeyCode::KeyF) {
commands.spawn((Projectile, Damage { value: 10.0 }));
}
// Triplicate all active projectiles
if input.just_pressed(KeyCode::KeyT) {
for projectile in projectiles.iter() {
// To triplicate a projectile we need to create 2 more clones
for _ in 0..2{
commands.clone_entity(projectile)
}
}
}
}
```
## Solution
### Commands
Add a `clone_entity` command to create a clone of an entity with all
components that can be cloned. Components that can't be cloned will be
ignored.
```rs
commands.clone_entity(entity)
```
If there is a need to configure the cloning process (like set to clone
recursively), there is a second command:
```rs
commands.clone_entity_with(entity, |builder| {
builder.recursive(true)
});
```
Both of these commands return `EntityCommands` of the cloned entity, so
the copy can be modified afterwards.
### Builder
All these commands use `EntityCloneBuilder` internally. If there is a
need to clone an entity using `World` instead, it is also possible:
```rs
let entity = world.spawn(Component).id();
let entity_clone = world.spawn_empty().id();
EntityCloneBuilder::new(&mut world).clone_entity(entity, entity_clone);
```
Builder has methods to `allow` or `deny` certain components during
cloning if required and can be extended by implementing traits on it.
This PR includes two `EntityCloneBuilder` extensions:
`CloneEntityWithObserversExt` to configure adding cloned entity to
observers of the original entity, and `CloneEntityRecursiveExt` to
configure cloning an entity recursively.
### Clone implementations
By default, all components that implement either `Clone` or `Reflect`
will be cloned (with `Clone`-based implementation preferred in case
component implements both).
This can be overriden on a per-component basis:
```rs
impl Component for SomeComponent {
const STORAGE_TYPE: StorageType = StorageType::Table;
fn get_component_clone_handler() -> ComponentCloneHandler {
// Don't clone this component
ComponentCloneHandler::Ignore
}
}
```
### `ComponentCloneHandlers`
Clone implementation specified in `get_component_clone_handler` will get
registered in `ComponentCloneHandlers` (stored in
`bevy_ecs::component::Components`) at component registration time.
The clone handler implementation provided by a component can be
overriden after registration like so:
```rs
let component_id = world.components().component_id::<Component>().unwrap()
world.get_component_clone_handlers_mut()
.set_component_handler(component_id, ComponentCloneHandler::Custom(component_clone_custom))
```
The default clone handler for all components that do not explicitly
define one (or don't derive `Component`) is
`component_clone_via_reflect` if `bevy_reflect` feature is enabled, and
`component_clone_ignore` (noop) otherwise.
Default handler can be overriden using
`ComponentCloneHandlers::set_default_handler`
### Handlers
Component clone handlers can be used to modify component cloning
behavior. The general signature for a handler that can be used in
`ComponentCloneHandler::Custom` is as follows:
```rs
pub fn component_clone_custom(
world: &mut DeferredWorld,
entity_cloner: &EntityCloner,
) {
// implementation
}
```
The `EntityCloner` implementation (used internally by
`EntityCloneBuilder`) assumes that after calling this custom handler,
the `target` entity has the desired version of the component from the
`source` entity.
### Builder handler overrides
Besides component-defined and world-overriden handlers,
`EntityCloneBuilder` also has a way to override handlers locally. It is
mainly used to allow configuration methods like `recursive` and
`add_observers`.
```rs
// From observer clone handler implementation
impl CloneEntityWithObserversExt for EntityCloneBuilder<'_> {
fn add_observers(&mut self, add_observers: bool) -> &mut Self {
if add_observers {
self.override_component_clone_handler::<ObservedBy>(ComponentCloneHandler::Custom(
component_clone_observed_by,
))
} else {
self.remove_component_clone_handler_override::<ObservedBy>()
}
}
}
```
## Testing
Includes some basic functionality tests and doctests.
Performance-wise this feature is the same as calling `clone` followed by
`insert` for every entity component. There is also some inherent
overhead due to every component clone handler having to access component
data through `World`, but this can be reduced without breaking current
public API in a later PR.
# Objective
There is currently no way of getting `QueryState` from `&World`, so it
is hard to, for example, iterate over all entities with a component,
only having `&World`.
## Solution
Add `try_new` function to `QueryState` that internally uses
`WorldQuery`'s `get_state`.
## Testing
No testing
# Objective
- Fixes#16406 even more. The previous implementation did not take into
account the depth of the requiree when setting the depth relative to the
required_by component.
## Solution
- Add the depth of the requiree!
## Testing
- Added a test.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Seemed to have missed the export of `DynamicComponentFetch` from #15593.
`TryFromFilteredError` which is returned by `impl
TryFrom<FiliteredEntityMut/Ref> for EntityRef/Mut` also seemed to have
been missing.
## Solution
Export both of them.
# Objective
- Fixes: #15603
## Solution
- Add an unsafe `get_mut_by_id_unchecked` to `EntityMut` that borrows
&self instead of &mut self, thereby allowing access to multiple
components simultaneously.
## Testing
- a unit test function `get_mut_by_id_unchecked` was added.
---------
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
Re-enable some tests in `entity_ref.rs` that are marked as `#[ignore]`,
but that pass after #14561.
## Solution
Remove `#[ignore]` from those tests.
# Objective
Bevy seems to want to standardize on "American English" spellings. Not
sure if this is laid out anywhere in writing, but see also #15947.
While perusing the docs for `typos`, I noticed that it has a `locale`
config option and tried it out.
## Solution
Switch to `en-us` locale in the `typos` config and run `typos -w`
## Migration Guide
The following methods or fields have been renamed from `*dependants*` to
`*dependents*`.
- `ProcessorAssetInfo::dependants`
- `ProcessorAssetInfos::add_dependant`
- `ProcessorAssetInfos::non_existent_dependants`
- `AssetInfo::dependants_waiting_on_load`
- `AssetInfo::dependants_waiting_on_recursive_dep_load`
- `AssetInfos::loader_dependants`
- `AssetInfos::remove_dependants_and_labels`
# Objective
- Closes#14774
## Solution
Added:
```rust
impl<'w, E, B: Bundle> Trigger<'w, E, B> {
pub fn components(&self) -> &[ComponentId];
}
```
I went with storing it in the trigger as a `SmallVec<[Component; 1]>`
because a singular target component will be the most common case, and it
remains the same size as `Vec<ComponentId>`.
## Testing
Added a test.
# Objective
Another clippy-lint fix: the goal is so that `ci lints` actually
displays the problems that a contributor caused, and not a bunch of
existing stuff in the repo. (when run on nightly)
## Solution
This fixes all but the `clippy::needless_lifetimes` lint, which will
result in substantially more fixes and be in other PR(s). I also
explicitly allow `non_local_definitions` since it is [not working
correctly, but will be
fixed](https://github.com/rust-lang/rust/issues/131643).
A few things were manually fixed: for example, some places had an
explicitly defined `div_ceil` function that was used, which is no longer
needed since this function is stable on unsigned integers. Also, empty
lines in doc comments were handled individually.
## Testing
I ran `cargo clippy --workspace --all-targets --all-features --fix
--allow-staged` with the `clippy::needless_lifetimes` lint marked as
`allow` in `Cargo.toml` to avoid fixing that too. It now passes with all
but the listed lint.
# Objective
`insert_or_spawn_batch` exists, but a version for just inserting doesn't
- Closes#2693
- Closes#8384
- Adopts/supersedes #8600
## Solution
Add `insert_batch`, along with the most common `insert` variations:
- `World::insert_batch`
- `World::insert_batch_if_new`
- `World::try_insert_batch`
- `World::try_insert_batch_if_new`
- `Commands::insert_batch`
- `Commands::insert_batch_if_new`
- `Commands::try_insert_batch`
- `Commands::try_insert_batch_if_new`
## Testing
Added tests, and added a benchmark for `insert_batch`.
Performance is slightly better than `insert_or_spawn_batch` when only
inserting:
<details>
<summary>old benchmark</summary>
This was before reworking it to remove the `UnsafeWorldCell`:
</details>
---
## Showcase
Usage is the same as `insert_or_spawn_batch`:
```
use bevy_ecs::{entity::Entity, world::World, component::Component};
#[derive(Component)]
struct A(&'static str);
#[derive(Component, PartialEq, Debug)]
struct B(f32);
let mut world = World::new();
let entity_a = world.spawn_empty().id();
let entity_b = world.spawn_empty().id();
world.insert_batch([
(entity_a, (A("a"), B(0.0))),
(entity_b, (A("b"), B(1.0))),
]);
assert_eq!(world.get::<B>(entity_a), Some(&B(0.0)));
```
# Objective
If a `Resource` implements `FromWorld` or `Default`, it's nicer to be
able to write:
```rust
let foo = world.get_resource_or_init::<Foo>();
```
Rather than:
```rust
let foo = world.get_resource_or_insert_with(Foo::default);
```
The latter is also not possible if a type implements `FromWorld` only,
and not `Default`.
## Solution
Added:
```rust
impl World {
pub fn get_resource_or_init<R: Resource + FromWorld>(&mut self) -> Mut<'_, R>;
}
```
Turns out all current in-engine uses of `get_resource_or_insert_with`
are exactly the above, so they've also been replaced.
## Testing
- Added a doc-test.
- Also added a doc-test for `World::get_resource_or_insert_with`.
# Objective
- Closes#15752
Calling the functions `App::observe` and `World::observe` doesn't make
sense because you're not "observing" the `App` or `World`, you're adding
an observer that listens for an event that occurs *within* the `World`.
We should rename them to better fit this.
## Solution
Renames:
- `App::observe` -> `App::add_observer`
- `World::observe` -> `World::add_observer`
- `Commands::observe` -> `Commands::add_observer`
- `EntityWorldMut::observe_entity` -> `EntityWorldMut::observe`
(Note this isn't a breaking change as the original rename was introduced
earlier this cycle.)
## Testing
Reusing current tests.
# Objective
After merging retained rendering world #15320, we now have a good way of
creating a link between worlds (*HIYAA intensifies*). This means that
`get_or_spawn` is no longer necessary for that function. Entity should
be opaque as the warning above `get_or_spawn` says. This is also part of
#15459.
I'm deprecating `get_or_spawn_batch` in a different PR in order to keep
the PR small in size.
## Solution
Deprecate `get_or_spawn` and replace it with `get_entity` in most
contexts. If it's possible to query `&RenderEntity`, then the entity is
synced and `render_entity.id()` is initialized in the render world.
## Migration Guide
If you are given an `Entity` and you want to do something with it, use
`Commands.entity(...)` or `World.entity(...)`. If instead you want to
spawn something use `Commands.spawn(...)` or `World.spawn(...)`. If you
are not sure if an entity exists, you can always use `get_entity` and
match on the `Option<...>` that is returned.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Following the pattern established in #15593, we can reduce the API
surface of `World` by providing a single function to grab both a
singular entity reference, or multiple entity references.
## Solution
The following functions can now also take multiple entity IDs and will
return multiple entity references back:
- `World::entity`
- `World::get_entity`
- `World::entity_mut`
- `World::get_entity_mut`
- `DeferredWorld::entity_mut`
- `DeferredWorld::get_entity_mut`
If you pass in X, you receive Y:
- give a single `Entity`, receive a single `EntityRef`/`EntityWorldMut`
(matches current behavior)
- give a `[Entity; N]`/`&[Entity; N]` (array), receive an equally-sized
`[EntityRef; N]`/`[EntityMut; N]`
- give a `&[Entity]` (slice), receive a
`Vec<EntityRef>`/`Vec<EntityMut>`
- give a `&EntityHashSet`, receive a
`EntityHashMap<EntityRef>`/`EntityHashMap<EntityMut>`
Note that `EntityWorldMut` is only returned in the single-entity case,
because having multiple at the same time would lead to UB. Also,
`DeferredWorld` receives an `EntityMut` in the single-entity case
because it does not allow structural access.
## Testing
- Added doc-tests on `World::entity`, `World::entity_mut`, and
`DeferredWorld::entity_mut`
- Added tests for aliased mutability and entity existence
---
## Showcase
<details>
<summary>Click to view showcase</summary>
The APIs for fetching `EntityRef`s and `EntityMut`s from the `World`
have been unified.
```rust
// This code will be referred to by subsequent code blocks.
let world = World::new();
let e1 = world.spawn_empty().id();
let e2 = world.spawn_empty().id();
let e3 = world.spawn_empty().id();
```
Querying for a single entity remains mostly the same:
```rust
// 0.14
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Option<EntityRef> = world.get_entity(e1);
let emut: Option<EntityWorldMut> = world.get_entity_mut(e1);
// 0.15
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Result<EntityRef, Entity> = world.get_entity(e1);
let emut: Result<EntityWorldMut, Entity> = world.get_entity_mut(e1);
```
Querying for multiple entities with an array has changed:
```rust
// 0.14
let erefs: [EntityRef; 2] = world.many_entities([e1, e2]);
let emuts: [EntityMut; 2] = world.many_entities_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_many_entities([e1, e2]);
let emuts: Result<[EntityMut; 2], QueryEntityError> = world.get_many_entities_mut([e1, e2]);
// 0.15
let erefs: [EntityRef; 2] = world.entity([e1, e2]);
let emuts: [EntityMut; 2] = world.entity_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_entity([e1, e2]);
let emuts: Result<[EntityMut; 2], EntityFetchError> = world.get_entity_mut([e1, e2]);
```
Querying for multiple entities with a slice has changed:
```rust
let ids = vec![e1, e2, e3]);
// 0.14
let erefs: Result<Vec<EntityRef>, Entity> = world.get_many_entities_dynamic(&ids[..]);
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_dynamic_mut(&ids[..]);
// 0.15
let erefs: Result<Vec<EntityRef>, Entity> = world.get_entity(&ids[..]);
let emuts: Result<Vec<EntityMut>, EntityFetchError> = world.get_entity_mut(&ids[..]);
let erefs: Vec<EntityRef> = world.entity(&ids[..]); // Newly possible!
let emuts: Vec<EntityMut> = world.entity_mut(&ids[..]); // Newly possible!
```
Querying for multiple entities with an `EntityHashSet` has changed:
```rust
let set = EntityHashSet::from_iter([e1, e2, e3]);
// 0.14
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_from_set_mut(&set);
// 0.15
let emuts: Result<EntityHashMap<EntityMut>, EntityFetchError> = world.get_entity_mut(&set);
let erefs: Result<EntityHashMap<EntityRef>, EntityFetchError> = world.get_entity(&set); // Newly possible!
let emuts: EntityHashMap<EntityMut> = world.entity_mut(&set); // Newly possible!
let erefs: EntityHashMap<EntityRef> = world.entity(&set); // Newly possible!
```
</details>
## Migration Guide
- `World::get_entity` now returns `Result<_, Entity>` instead of
`Option<_>`.
- Use `world.get_entity(..).ok()` to return to the previous behavior.
- `World::get_entity_mut` and `DeferredWorld::get_entity_mut` now return
`Result<_, EntityFetchError>` instead of `Option<_>`.
- Use `world.get_entity_mut(..).ok()` to return to the previous
behavior.
- Type inference for `World::entity`, `World::entity_mut`,
`World::get_entity`, `World::get_entity_mut`,
`DeferredWorld::entity_mut`, and `DeferredWorld::get_entity_mut` has
changed, and might now require the input argument's type to be
explicitly written when inside closures.
- The following functions have been deprecated, and should be replaced
as such:
- `World::many_entities` -> `World::entity::<[Entity; N]>`
- `World::many_entities_mut` -> `World::entity_mut::<[Entity; N]>`
- `World::get_many_entities` -> `World::get_entity::<[Entity; N]>`
- `World::get_many_entities_dynamic` -> `World::get_entity::<&[Entity]>`
- `World::get_many_entities_mut` -> `World::get_entity_mut::<[Entity;
N]>`
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_dynamic_mut` ->
`World::get_entity_mut::<&[Entity]>1
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_from_set_mut` ->
`World::get_entity_mut::<&EntityHashSet>`
- The equivalent return type has changed from `Result<Vec<EntityMut>,
QueryEntityError>` to `Result<EntityHashMap<EntityMut>,
EntityFetchError>`. If necessary, you can still convert the
`EntityHashMap` into a `Vec`.
## Objective
The new Required Components feature (#14791) in Bevy allows spawning a
fixed set of components with a single method with cool require macro.
However, there's currently no corresponding method to remove all those
components together. This makes it challenging to keep insertion and
removal code in sync, especially for simple using cases.
```rust
#[derive(Component)]
#[require(Y)]
struct X;
#[derive(Component, Default)]
struct Y;
world.entity_mut(e).insert(X); // Spawns both X and Y
world.entity_mut(e).remove::<X>();
world.entity_mut(e).remove::<Y>(); // We need to manually remove dependencies without any sync with the `require` macro
```
## Solution
Simplifies component management by providing operations for removal
required components.
This PR introduces simple 'footgun' methods to removes all components of
this bundle and its required components.
Two new methods are introduced:
For Commands:
```rust
commands.entity(e).remove_with_requires::<B>();
```
For World:
```rust
world.entity_mut(e).remove_with_requires::<B>();
```
For performance I created new field in Bundels struct. This new field
"contributed_bundle_ids" contains cached ids for dynamic bundles
constructed from bundle_info.cintributed_components()
## Testing
The PR includes three test cases:
1. Removing a single component with requirements using World.
2. Removing a bundle with requirements using World.
3. Removing a single component with requirements using Commands.
4. Removing a single component with **runtime** requirements using
Commands
These tests ensure the feature works as expected across different
scenarios.
## Showcase
Example:
```rust
use bevy_ecs::prelude::*;
#[derive(Component)]
#[require(Y)]
struct X;
#[derive(Component, Default)]
#[require(Z)]
struct Y;
#[derive(Component, Default)]
struct Z;
#[derive(Component)]
struct W;
let mut world = World::new();
// Spawn an entity with X, Y, Z, and W components
let entity = world.spawn((X, W)).id();
assert!(world.entity(entity).contains::<X>());
assert!(world.entity(entity).contains::<Y>());
assert!(world.entity(entity).contains::<Z>());
assert!(world.entity(entity).contains::<W>());
// Remove X and required components Y, Z
world.entity_mut(entity).remove_with_requires::<X>();
assert!(!world.entity(entity).contains::<X>());
assert!(!world.entity(entity).contains::<Y>());
assert!(!world.entity(entity).contains::<Z>());
assert!(world.entity(entity).contains::<W>());
```
## Motivation for PR
#15580
## Performance
I made simple benchmark
```rust
let mut world = World::default();
let entity = world.spawn_empty().id();
let steps = 100_000_000;
let start = std::time::Instant::now();
for _ in 0..steps {
world.entity_mut(entity).insert(X);
world.entity_mut(entity).remove::<(X, Y, Z, W)>();
}
let end = std::time::Instant::now();
println!("normal remove: {:?} ", (end - start).as_secs_f32());
println!("one remove: {:?} micros", (end - start).as_secs_f64() / steps as f64 * 1_000_000.0);
let start = std::time::Instant::now();
for _ in 0..steps {
world.entity_mut(entity).insert(X);
world.entity_mut(entity).remove_with_requires::<X>();
}
let end = std::time::Instant::now();
println!("remove_with_requires: {:?} ", (end - start).as_secs_f32());
println!("one remove_with_requires: {:?} micros", (end - start).as_secs_f64() / steps as f64 * 1_000_000.0);
```
Output:
CPU: Amd Ryzen 7 2700x
```bash
normal remove: 17.36135
one remove: 0.17361348299999999 micros
remove_with_requires: 17.534006
one remove_with_requires: 0.17534005400000002 micros
```
NOTE: I didn't find any tests or mechanism in the repository to update
BundleInfo after creating new runtime requirements with an existing
BundleInfo. So this PR also does not contain such logic.
## Future work (outside this PR)
Create cache system for fast removing components in "safe" mode, where
"safe" mode is remove only required components that will be no longer
required after removing root component.
---------
Co-authored-by: a.yamaev <a.yamaev@smartengines.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Support accessing dynamic resources in a dynamic system, including
accessing them by component id. This is similar to how dynamic
components can be queried using `Query<FilteredEntityMut>`.
## Solution
Create `FilteredResources` and `FilteredResourcesMut` types that act
similar to `FilteredEntityRef` and `FilteredEntityMut` and that can be
used as system parameters.
## Example
```rust
// Use `FilteredResourcesParamBuilder` to declare access to resources.
let system = (FilteredResourcesParamBuilder::new(|builder| {
builder.add_read::<B>().add_read::<C>();
}),)
.build_state(&mut world)
.build_system(resource_system);
world.init_resource::<A>();
world.init_resource::<C>();
fn resource_system(res: FilteredResources) {
// The resource exists, but we have no access, so we can't read it.
assert!(res.get::<A>().is_none());
// The resource doesn't exist, so we can't read it.
assert!(res.get::<B>().is_none());
// The resource exists and we have access, so we can read it.
let c = res.get::<C>().unwrap();
// The type parameter can be left out if it can be determined from use.
let c: Res<C> = res.get().unwrap();
}
```
## Future Work
As a follow-up PR, `ReflectResource` can be modified to take `impl
Into<FilteredResources>`, similar to how `ReflectComponent` takes `impl
Into<FilteredEntityRef>`. That will allow dynamic resources to be
accessed using reflection.
# Objective
The current observers have some unfortunate footguns where you can end
up confused about what is actually being observed. For apps you can
chain observe like `app.observe(..).observe(..)` which works like you
would expect, but if you try the same with world the first `observe()`
will return the `EntityWorldMut` for the created observer, and the
second `observe()` will only observe on the observer entity. It took
several hours for multiple people on discord to figure this out, which
is not a great experience.
## Solution
Rename `observe` on entities to `observe_entity`. It's slightly more
verbose when you know you have an entity, but it feels right to me that
observers for specific things have more specific naming, and it prevents
this issue completely.
Another possible solution would be to unify `observe` on `App` and
`World` to have the same kind of return type, but I'm not sure exactly
what that would look like.
## Testing
Simple name change, so only concern is docs really.
---
## Migration Guide
The `observe()` method on entities has been renamed to
`observe_entity()` to prevent confusion about what is being observed in
some cases.
# Objective
Fixes#14511.
`despawn` allows you to remove entities from the world. However, if the
entity does not exist, it emits a warning. This may not be intended
behavior for many users who have use cases where they need to call
`despawn` regardless of if the entity actually exists (see the issue),
or don't care in general if the entity already doesn't exist.
(Also trying to gauge interest on if this feature makes sense, I'd
personally love to have it, but I could see arguments that this might be
a footgun. Just trying to help here 😄 If there's no contention I could
also implement this for `despawn_recursive` and `despawn_descendants` in
the same PR)
## Solution
Add `try_despawn`, `try_despawn_recursive` and
`try_despawn_descendants`.
Modify `World::despawn_with_caller` to also take in a `warn` boolean
argument, which is then considered when logging the warning. Set
`log_warning` to `true` in the case of `despawn`, and `false` in the
case of `try_despawn`.
## Testing
Ran `cargo run -p ci` on macOS, it seemed fine.
# Objective
- Closes#15577
## Solution
The following functions can now also take multiple component IDs and
return multiple pointers back:
- `EntityRef::get_by_id`
- `EntityMut::get_by_id`
- `EntityMut::into_borrow_by_id`
- `EntityMut::get_mut_by_id`
- `EntityMut::into_mut_by_id`
- `EntityWorldMut::get_by_id`
- `EntityWorldMut::into_borrow_by_id`
- `EntityWorldMut::get_mut_by_id`
- `EntityWorldMut::into_mut_by_id`
If you pass in X, you receive Y:
- give a single `ComponentId`, receive a single `Ptr`/`MutUntyped`
- give a `[ComponentId; N]` (array), receive a `[Ptr; N]`/`[MutUntyped;
N]`
- give a `&[ComponentId; N]` (array), receive a `[Ptr; N]`/`[MutUntyped;
N]`
- give a `&[ComponentId]` (slice), receive a
`Vec<Ptr>`/`Vec<MutUntyped>`
- give a `&HashSet<ComponentId>`, receive a `HashMap<ComponentId,
Ptr>`/`HashMap<ComponentId, MutUntyped>`
## Testing
- Added 4 new tests.
---
## Migration Guide
- The following functions now return an `Result<_,
EntityComponentError>` instead of a `Option<_>`: `EntityRef::get_by_id`,
`EntityMut::get_by_id`, `EntityMut::into_borrow_by_id`,
`EntityMut::get_mut_by_id`, `EntityMut::into_mut_by_id`,
`EntityWorldMut::get_by_id`, `EntityWorldMut::into_borrow_by_id`,
`EntityWorldMut::get_mut_by_id`, `EntityWorldMut::into_mut_by_id`
# Objective
Fixes#15540
End-users risk using `World::flush_commands` instead of `World::flush`,
which panics if any queued commands are `spawn`. Hiding
`World::flush_commands` would help avoid calling a potentially panicky
function, and helps alleviate end-user API confusion.
## Solution
This PR updates the function visibility to crate-level, like
`World::flush_entities`, hiding it from the end-user while still making
it accessible for the tests that are currently set up.
## Testing
The change was tested by executing the available tests for `bevy_ecs`.
From what I've gathered, `World::flush_commands` is not used in any
other bevy crate. If further testing is recommended, please inform me!
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#15367.
Currently, required components can only be defined through the `require`
macro attribute. While this should be used in most cases, there are also
several instances where you may want to define requirements at runtime,
commonly in plugins.
Example use cases:
- Require components only if the relevant optional plugins are enabled.
For example, a `SleepTimer` component (for physics) is only relevant if
the `SleepPlugin` is enabled.
- Third party crates can define their own requirements for first party
types. For example, "each `Handle<Mesh>` should require my custom
rendering data components". This also gets around the orphan rule.
- Generic plugins that add marker components based on the existence of
other components, like a generic `ColliderPlugin<C: AnyCollider>` that
wants to add a `ColliderMarker` component for all types of colliders.
- This is currently relevant for the retained render world in #15320.
The `ExtractComponentPlugin<C>` should add `SyncToRenderWorld` to all
components that should be extracted. This is currently done with
observers, which is more expensive than required components, and causes
archetype moves.
- Replace some built-in components with custom versions. For example, if
`GlobalTransform` required `Transform` through `TransformPlugin`, but we
wanted to use a `CustomTransform` type, we could replace
`TransformPlugin` with our own plugin. (This specific example isn't
good, but there are likely better use cases where this may be useful)
See #15367 for more in-depth reasoning.
## Solution
Add `register_required_components::<T, R>` and
`register_required_components_with::<T, R>` methods for `Default` and
custom constructors respectively. These methods exist on `App` and
`World`.
```rust
struct BirdPlugin;
impl Plugin for BirdPlugin {
fn plugin(app: &mut App) {
// Make `Bird` require `Wings` with a `Default` constructor.
app.register_required_components::<Bird, Wings>();
// Make `Wings` require `FlapSpeed` with a custom constructor.
// Fun fact: Some hummingbirds can flutter their wings 80 times per second!
app.register_required_components_with::<Wings, FlapSpeed>(|| FlapSpeed::from_duration(1.0 / 80.0));
}
}
```
The custom constructor is a function pointer to match the `require` API,
though it could take a raw value too.
Requirement inheritance works similarly as with the `require` attribute.
If `Bird` required `FlapSpeed` directly, it would take precedence over
indirectly requiring it through `Wings`. The same logic applies to all
levels of the inheritance tree.
Note that registering the same component requirement more than once will
panic, similarly to trying to add multiple component hooks of the same
type to the same component. This avoids constructor conflicts and
confusing ordering issues.
### Implementation
Runtime requirements have two additional challenges in comparison to the
`require` attribute.
1. The `require` attribute uses recursion and macros with clever
ordering to populate hash maps of required components for each component
type. The expected semantics are that "more specific" requirements
override ones deeper in the inheritance tree. However, at runtime, there
is no representation of how "specific" each requirement is.
2. If you first register the requirement `X -> Y`, and later register `Y
-> Z`, then `X` should also indirectly require `Z`. However, `Y` itself
doesn't know that it is required by `X`, so it's not aware that it
should update the list of required components for `X`.
My solutions to these problems are:
1. Store the depth in the inheritance tree for each entry of a given
component's `RequiredComponents`. This is used to determine how
"specific" each requirement is. For `require`-based registration, these
depths are computed as part of the recursion.
2. Store and maintain a `required_by` list in each component's
`ComponentInfo`, next to `required_components`. For `require`-based
registration, these are also added after each registration, as part of
the recursion.
When calling `register_required_components`, it works as follows:
1. Get the required components of `Foo`, and check that `Bar` isn't
already a *direct* requirement.
3. Register `Bar` as a required component for `Foo`, and add `Foo` to
the `required_by` list for `Bar`.
4. Find and register all indirect requirements inherited from `Bar`,
adding `Foo` to the `required_by` list for each component.
5. Iterate through components that require `Foo`, registering the new
inherited requires for them as indirect requirements.
The runtime registration is likely slightly more expensive than the
`require` version, but it is a one-time cost, and quite negligible in
practice, unless projects have hundreds or thousands of runtime
requirements. I have not benchmarked this however.
This does also add a small amount of extra cost to the `require`
attribute for updating `required_by` lists, but I expect it to be very
minor.
## Testing
I added some tests that are copies of the `require` versions, as well as
some tests that are more specific to the runtime implementation. I might
add a few more tests though.
## Discussion
- Is `register_required_components` a good name? Originally I went for
`register_component_requirement` to be consistent with
`register_component_hooks`, but the general feature is often referred to
as "required components", which is why I changed it to
`register_required_components`.
- Should we *not* panic for duplicate requirements? If so, should they
just be ignored, or should the latest registration overwrite earlier
ones?
- If we do want to panic for duplicate, conflicting registrations,
should we at least not panic if the registrations are *exactly* the
same, i.e. same component and same constructor? The current
implementation panics for all duplicate direct registrations regardless
of the constructor.
## Next Steps
- Allow `register_required_components` to take a `Bundle` instead of a
single required component.
- I could also try to do it in this PR if that would be preferable.
- Not directly related, but archetype invariants?
