# Background
In `no_std` compatible crates, there is often an `std` feature which
will allow access to the standard library. Currently, with the `std`
feature _enabled_, the
[`std::prelude`](https://doc.rust-lang.org/std/prelude/index.html) is
implicitly imported in all modules. With the feature _disabled_, instead
the [`core::prelude`](https://doc.rust-lang.org/core/prelude/index.html)
is implicitly imported. This creates a subtle and pervasive issue where
`alloc` items _may_ be implicitly included (if `std` is enabled), or
must be explicitly included (if `std` is not enabled).
# Objective
- Make the implicit imports for `no_std` crates consistent regardless of
what features are/not enabled.
## Solution
- Replace the `cfg_attr` "double negative" `no_std` attribute with
conditional compilation to _include_ `std` as an external crate.
```rust
// Before
#![cfg_attr(not(feature = "std"), no_std)]
// After
#![no_std]
#[cfg(feature = "std")]
extern crate std;
```
- Fix imports that are currently broken but are only now visible with
the above fix.
## Testing
- CI
## Notes
I had previously used the "double negative" version of `no_std` based on
general consensus that it was "cleaner" within the Rust embedded
community. However, this implicit prelude issue likely was considered
when forming this consensus. I believe the reason why is the items most
affected by this issue are provided by the `alloc` crate, which is
rarely used within embedded but extensively used within Bevy.
## 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
- 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
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
- 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#15676
## Solution
`remove` returns the removed item
Add `take`
## Testing
None yet
## Migration Guide
If you don't need the returned value from `remove`, discard it.
# 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`.
Previous PR https://github.com/bevyengine/bevy/pull/14549 was closed in
error and couldn't be reopened since I had updated the branch
😿
# Objective
Fixes#14465
## Solution
`ReflectMapEntities` now works similarly to `MapEntities` in that it
works on the reflected value itself rather than the component in the
world after insertion. This makes it so that observers see the remapped
entities on insertion rather than the entity IDs from the scene.
`ReflectMapEntities` now works for both components and resources, so we
only need the one.
## Testing
* New unit test for `Observer`s + `DynamicScene`s
* New unit test for `Observer`s + `Scene`s
* Open to suggestions for other tests!
---
## Migration Guide
- Consumers of `ReflectMapEntities` will need to call `map_entities` on
values prior to inserting them into the world.
- Implementors of `MapEntities` will need to remove the `mappings`
method, which is no longer needed for `ReflectMapEntities` and has been
removed from the trait.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Hennadii Chernyshchyk <genaloner@gmail.com>
# Objective
- Provide a generic and _reflectable_ way to iterate over contained
entities
## Solution
Adds two new traits:
* `VisitEntities`: Reflectable iteration, accepts a closure rather than
producing an iterator. Implemented by default for `IntoIterator`
implementing types. A proc macro is also provided.
* A `Mut` variant of the above. Its derive macro uses the same field
attribute to avoid repetition.
## Testing
Added a test for `VisitEntities` that also transitively tests its derive
macro as well as the default `MapEntities` impl.
# Objective
- Resolves#15453
## Solution
- Added new `World::resource_id` and `World::register_resource` methods
to support this feature
- Added new `ReflectResource::register_resource` method, and new pointer
to this new function
- Added new `ReflectComponent::register_component`
## Testing
- Tested this locally, but couldn't test the entire crate locally, just
this new feature, expect that CI will do the rest of the work.
---
## Showcase
```rs
#[derive(Component, Reflect)]
#[reflect(Component)]
struct MyComp;
let mut world = World::new();
let mut registry = TypeRegistration::of::<MyComp>();
registry.insert::<ReflectComponent>(FromType::<MyComp>::from_type());
let data = registry.data::<ReflectComponent>().unwrap();
// Its now possible to register the Component in the world this way
let component_id = data.register_component(&mut world);
// They will be the same
assert_eq!(component_id, world.component_id::<MyComp>().unwrap());
```
```rs
#[derive(Resource, Reflect)]
#[reflect(Resource)]
struct MyResource;
let mut world = World::new();
let mut registry = TypeRegistration::of::<MyResource>();
registry.insert::<ReflectResource>(FromType::<MyResource>::from_type());
let data = registry.data::<ReflectResource>().unwrap();
// Same with resources
let component_id = data.register_resource(&mut world);
// They match
assert_eq!(component_id, world.resource_id::<MyResource>().unwrap());
```
# Objective
- Fixes#6370
- Closes#6581
## Solution
- Added the following lints to the workspace:
- `std_instead_of_core`
- `std_instead_of_alloc`
- `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.
## Testing
- Ran CI locally
## Migration Guide
The MSRV is now 1.81. Please update to this version or higher.
## Notes
- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Fixes#15106
## Solution
- Trivial refactor to rename the method. The duplicate method `push` was
removed as well. This will simpify the API and make the semantics more
clear. `Add` implies that the action happens immediately, whereas in
reality, the command is queued to be run eventually.
- `ChildBuilder::add_command` has similarly been renamed to
`queue_command`.
## Testing
Unit tests should suffice for this simple refactor.
---
## Migration Guide
- `Commands::add` and `Commands::push` have been replaced with
`Commnads::queue`.
- `ChildBuilder::add_command` has been renamed to
`ChildBuilder::queue_command`.
# Objective
- Finish resolving https://github.com/bevyengine/bevy/issues/15125
- Inserting bundles was implemented in
https://github.com/bevyengine/bevy/pull/15128 but removing bundles still
needed to be implemented.
## Solution
- Modified `bevy_ecs::reflect::entity_commands::remove_reflect` to
handle both components and bundles
- Modified documentation of `ReflectCommandExt` methods to reflect that
one can now use bundles with these commands.
## Testing
- Three tests were added to match the ones for inserting components.
# Objective
The code to create `ReflectComponent` and `ReflectResource` instances
manually constructs a `Mut<dyn Reflect>` by copying everything but
`value`. That can be done more concisely and better respecting
encapsulation by calling the `map_unchanged()` method.
## Solution
Use `map_unchanged` instead of creating a `Mut` manually.
---------
Co-authored-by: radiish <cb.setho@gmail.com>
# Objective
- Implements the [Unique Reflect
RFC](https://github.com/nicopap/rfcs/blob/bevy-reflect-api/rfcs/56-better-reflect.md).
## Solution
- Implements the RFC.
- This implementation differs in some ways from the RFC:
- In the RFC, it was suggested `Reflect: Any` but `PartialReflect:
?Any`. During initial implementation I tried this, but we assume the
`PartialReflect: 'static` in a lot of places and the changes required
crept out of the scope of this PR.
- `PartialReflect::try_into_reflect` originally returned `Option<Box<dyn
Reflect>>` but i changed this to `Result<Box<dyn Reflect>, Box<dyn
PartialReflect>>` since the method takes by value and otherwise there
would be no way to recover the type. `as_full` and `as_full_mut` both
still return `Option<&(mut) dyn Reflect>`.
---
## Changelog
- Added `PartialReflect`.
- `Reflect` is now a subtrait of `PartialReflect`.
- Moved most methods on `Reflect` to the new `PartialReflect`.
- Added `PartialReflect::{as_partial_reflect, as_partial_reflect_mut,
into_partial_reflect}`.
- Added `PartialReflect::{try_as_reflect, try_as_reflect_mut,
try_into_reflect}`.
- Added `<dyn PartialReflect>::{try_downcast_ref, try_downcast_mut,
try_downcast, try_take}` supplementing the methods on `dyn Reflect`.
## Migration Guide
- Most instances of `dyn Reflect` should be changed to `dyn
PartialReflect` which is less restrictive, however trait bounds should
generally stay as `T: Reflect`.
- The new `PartialReflect::{as_partial_reflect, as_partial_reflect_mut,
into_partial_reflect, try_as_reflect, try_as_reflect_mut,
try_into_reflect}` methods as well as `Reflect::{as_reflect,
as_reflect_mut, into_reflect}` will need to be implemented for manual
implementors of `Reflect`.
## Future Work
- This PR is designed to be followed up by another "Unique Reflect Phase
2" that addresses the following points:
- Investigate making serialization revolve around `Reflect` instead of
`PartialReflect`.
- [Remove the `try_*` methods on `dyn PartialReflect` since they are
stop
gaps](https://github.com/bevyengine/bevy/pull/7207#discussion_r1083476050).
- Investigate usages like `ReflectComponent`. In the places they
currently use `PartialReflect`, should they be changed to use `Reflect`?
- Merging this opens the door to lots of reflection features we haven't
been able to implement.
- We could re-add [the `Reflectable`
trait](8e3488c880/crates/bevy_reflect/src/reflect.rs (L337-L342))
and make `FromReflect` a requirement to improve [`FromReflect`
ergonomics](https://github.com/bevyengine/rfcs/pull/59). This is
currently not possible because dynamic types cannot sensibly be
`FromReflect`.
- Since this is an alternative to #5772, #5781 would be made cleaner.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
- While developing a debug tool I saw the gap where it was not possible
to get all existing states from a World using reflection.
- This PR allows to iterate over all `States` types that exist in a
world, and modify them in case they implement `FreelyMutableState`.
- Two new methods are available on `App` and `SubApp` as helper to
register the data types:
- `register_state_reflect` and `register_mutable_state_reflect`
## Solution
- Two new data types are added:
- `ReflectState`: Allows to extract the current value of a state from
the World.
- `ReflectFreelyMutableState`: Allows to set the next state in a world,
similar to call `NextState::set`.
- There is no distinction between `States`, `SubStates` and
`ComputedStates`:
- `States` can register both `ReflectState` and
`ReflectFreelyMutableState`.
- `SubStates` can register both `ReflectState` and
`ReflectFreelyMutableState`.
- `ComputedStates` can register only `ReflectState` .
## Testing
- Added tests inside the `bevy_state` crate.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
# Objective
#13152 added support for reflecting functions. Now, we need a way to
register those functions such that they may be accessed anywhere within
the ECS.
## Solution
Added a `FunctionRegistry` type similar to `TypeRegistry`.
This allows a function to be registered and retrieved by name.
```rust
fn foo() -> i32 {
123
}
let mut registry = FunctionRegistry::default();
registry.register("my_function", foo);
let function = registry.get_mut("my_function").unwrap();
let value = function.call(ArgList::new()).unwrap().unwrap_owned();
assert_eq!(value.downcast_ref::<i32>(), Some(&123));
```
Additionally, I added an `AppFunctionRegistry` resource which wraps a
`FunctionRegistryArc`. Functions can be registered into this resource
using `App::register_function` or by getting a mutable reference to the
resource itself.
### Limitations
#### `Send + Sync`
In order to get this registry to work across threads, it needs to be
`Send + Sync`. This means that `DynamicFunction` needs to be `Send +
Sync`, which means that its internal function also needs to be `Send +
Sync`.
In most cases, this won't be an issue because standard Rust functions
(the type most likely to be registered) are always `Send + Sync`.
Additionally, closures tend to be `Send + Sync` as well, granted they
don't capture any `!Send` or `!Sync` variables.
This PR adds this `Send + Sync` requirement, but as mentioned above, it
hopefully shouldn't be too big of an issue.
#### Closures
Unfortunately, closures can't be registered yet. This will likely be
explored and added in a followup PR.
### Future Work
Besides addressing the limitations listed above, another thing we could
look into is improving the lookup of registered functions. One aspect is
in the performance of hashing strings. The other is in the developer
experience of having to call `std::any::type_name_of_val` to get the
name of their function (assuming they didn't give it a custom name).
## Testing
You can run the tests locally with:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Added `FunctionRegistry`
- Added `AppFunctionRegistry` (a `Resource` available from `bevy_ecs`)
- Added `FunctionRegistryArc`
- Added `FunctionRegistrationError`
- Added `reflect_functions` feature to `bevy_ecs` and `bevy_app`
- `FunctionInfo` is no longer `Default`
- `DynamicFunction` now requires its wrapped function be `Send + Sync`
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
`DynamicFunction` (both those created manually and those created with
`IntoFunction`), now require `Send + Sync`. All standard Rust functions
should meet that requirement. Closures, on the other hand, may not if
they capture any `!Send` or `!Sync` variables from its environment.
# Objective
- Make it possible to know *what* changed your component or resource.
- Common need when debugging, when you want to know the last code
location that mutated a value in the ECS.
- This feature would be very useful for the editor alongside system
stepping.
## Solution
- Adds the caller location to column data.
- Mutations now `track_caller` all the way up to the public API.
- Commands that invoke these functions immediately call
`Location::caller`, and pass this into the functions, instead of the
functions themselves attempting to get the caller. This would not work
for commands which are deferred, as the commands are executed by the
scheduler, not the user's code.
## Testing
- The `component_change_detection` example now shows where the component
was mutated:
```
2024-07-28T06:57:48.946022Z INFO component_change_detection: Entity { index: 1, generation: 1 }: New value: MyComponent(0.0)
2024-07-28T06:57:49.004371Z INFO component_change_detection: Entity { index: 1, generation: 1 }: New value: MyComponent(1.0)
2024-07-28T06:57:49.012738Z WARN component_change_detection: Change detected!
-> value: Ref(MyComponent(1.0))
-> added: false
-> changed: true
-> changed by: examples/ecs/component_change_detection.rs:36:23
```
- It's also possible to inspect change location from a debugger:
<img width="608" alt="image"
src="https://github.com/user-attachments/assets/c90ecc7a-0462-457a-80ae-42e7f5d346b4">
---
## Changelog
- Added source locations to ECS change detection behind the
`track_change_detection` flag.
## Migration Guide
- Added `changed_by` field to many internal ECS functions used with
change detection when the `track_change_detection` feature flag is
enabled. Use Location::caller() to provide the source of the function
call.
---------
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# 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
- 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
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
- `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
- 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
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
- 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
- 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
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
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
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
- `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
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
- Shorten paths by removing unnecessary prefixes
## Solution
- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
# Objective
- `insert_reflect` relies on `reflect_type_path`, which doesn't gives
the actual type path for object created by `clone_value`, leading to an
unexpected panic. This is a workaround for it.
- Fix#10590
## Solution
- Tries to get type path from `get_represented_type_info` if get failed
from `reflect_type_path`.
---
## Defect remaining
- `get_represented_type_info` implies a shortage on performance than
using `TypeRegistry`.
# Objective
- There is a specialized hasher for entities:
[`EntityHashMap`](https://docs.rs/bevy/latest/bevy/utils/type.EntityHashMap.html)
- [`EntityMapper`] currently uses a normal `HashMap<Entity, Entity>`
- Fixes#10391
## Solution
- Replace the normal `HashMap` with the more performant `EntityHashMap`
## Questions
- This does change public API. Should a system be implemented to help
migrate code?
- Perhaps an `impl From<HashMap<K, V, S>> for EntityHashMap<K, V>`
- I updated to docs for each function that I changed, but I may have
missed something
---
## Changelog
- Changed `EntityMapper` to use `EntityHashMap` instead of normal
`HashMap`
## Migration Guide
If you are using the following types, update their listed methods to use
the new `EntityHashMap`. `EntityHashMap` has the same methods as the
normal `HashMap`, so you just need to replace the name.
### `EntityMapper`
- `get_map`
- `get_mut_map`
- `new`
- `world_scope`
### `ReflectMapEntities`
- `map_all_entities`
- `map_entities`
- `write_to_world`
### `InstanceInfo`
- `entity_map`
- This is a property, not a method.
---
This is my first time contributing in a while, and I'm not familiar with
the usage of `EntityMapper`. I changed the type definition and fixed all
errors, but there may have been things I've missed. Please keep an eye
out for me!
# Objective
- Followup to #7184.
- ~Deprecate `TypeUuid` and remove its internal references.~ No longer
part of this PR.
- Use `TypePath` for the type registry, and (de)serialisation instead of
`std::any::type_name`.
- Allow accessing type path information behind proxies.
## Solution
- Introduce methods on `TypeInfo` and friends for dynamically querying
type path. These methods supersede the old `type_name` methods.
- Remove `Reflect::type_name` in favor of `DynamicTypePath::type_path`
and `TypeInfo::type_path_table`.
- Switch all uses of `std::any::type_name` in reflection, non-debugging
contexts to use `TypePath`.
---
## Changelog
- Added `TypePathTable` for dynamically accessing methods on `TypePath`
through `TypeInfo` and the type registry.
- Removed `type_name` from all `TypeInfo`-like structs.
- Added `type_path` and `type_path_table` methods to all `TypeInfo`-like
structs.
- Removed `Reflect::type_name` in favor of
`DynamicTypePath::reflect_type_path` and `TypeInfo::type_path`.
- Changed the signature of all `DynamicTypePath` methods to return
strings with a static lifetime.
## Migration Guide
- Rely on `TypePath` instead of `std::any::type_name` for all stability
guarantees and for use in all reflection contexts, this is used through
with one of the following APIs:
- `TypePath::type_path` if you have a concrete type and not a value.
- `DynamicTypePath::reflect_type_path` if you have an `dyn Reflect`
value without a concrete type.
- `TypeInfo::type_path` for use through the registry or if you want to
work with the represented type of a `DynamicFoo`.
- Remove `type_name` from manual `Reflect` implementations.
- Use `type_path` and `type_path_table` in place of `type_name` on
`TypeInfo`-like structs.
- Use `get_with_type_path(_mut)` over `get_with_type_name(_mut)`.
## Note to reviewers
I think if anything we were a little overzealous in merging #7184 and we
should take that extra care here.
In my mind, this is the "point of no return" for `TypePath` and while I
think we all agree on the design, we should carefully consider if the
finer details and current implementations are actually how we want them
moving forward.
For example [this incorrect `TypePath` implementation for
`String`](3fea3c6c0b/crates/bevy_reflect/src/impls/std.rs (L90))
(note that `String` is in the default Rust prelude) snuck in completely
under the radar.
# Objective
Fix#4278Fix#5504Fix#9422
Provide safe ways to borrow an entire entity, while allowing disjoint
mutable access. `EntityRef` and `EntityMut` are not suitable for this,
since they provide access to the entire world -- they are just helper
types for working with `&World`/`&mut World`.
This has potential uses for reflection and serialization
## Solution
Remove `EntityRef::world`, which allows it to soundly be used within
queries.
`EntityMut` no longer supports structural world mutations, which allows
multiple instances of it to exist for different entities at once.
Structural world mutations are performed using the new type
`EntityWorldMut`.
```rust
fn disjoint_system(
q2: Query<&mut A>,
q1: Query<EntityMut, Without<A>>,
) { ... }
let [entity1, entity2] = world.many_entities_mut([id1, id2]);
*entity1.get_mut::<T>().unwrap() = *entity2.get().unwrap();
for entity in world.iter_entities_mut() {
...
}
```
---
## Changelog
- Removed `EntityRef::world`, to fix a soundness issue with queries.
+ Removed the ability to structurally mutate the world using
`EntityMut`, which allows it to be used in queries.
+ Added `EntityWorldMut`, which is used to perform structural mutations
that are no longer allowed using `EntityMut`.
## Migration Guide
**Note for maintainers: ensure that the guide for #9604 is updated
accordingly.**
Removed the method `EntityRef::world`, to fix a soundness issue with
queries. If you need access to `&World` while using an `EntityRef`,
consider passing the world as a separate parameter.
`EntityMut` can no longer perform 'structural' world mutations, such as
adding or removing components, or despawning the entity. Additionally,
`EntityMut::world`, `EntityMut::world_mut` , and
`EntityMut::world_scope` have been removed.
Instead, use the newly-added type `EntityWorldMut`, which is a helper
type for working with `&mut World`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
To enable non exclusive system usage of reflected components and make
reflection more ergonomic to use by making it more in line with standard
entity commands.
## Solution
- Implements a new `EntityCommands` extension trait for reflection
related functions in the reflect module of bevy_ecs.
- Implements 4 new commands, `insert_reflect`,
`insert_reflect_with_registry`, `remove_reflect`, and
`remove_reflect_with_registry`. Both insert commands take a `Box<dyn
Reflect>` component while the remove commands take the component type
name.
- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module. (Might be worth making these just public to enable user end
custom entity commands in a different pr)
- Added basic tests to ensure the commands are actually working.
- Documentation of functions.
---
## Changelog
Added:
- Implements 4 new commands on the new entity commands extension.
- `insert_reflect`
- `remove_reflect`
- `insert_reflect_with_registry`
- `remove_reflect_with_registry`
The commands operate the same except the with_registry commands take a
generic parameter for a resource that implements `AsRef<TypeRegistry>`.
Otherwise the default commands use the `AppTypeRegistry` for reflection
data.
Changed:
- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module.
> Hopefully this time it works. Please don't make me rebase again ☹
# Objective
- Fixes#9321
## Solution
- `EntityMap` has been replaced by a simple `HashMap<Entity, Entity>`.
---
## Changelog
- `EntityMap::world_scope` has been replaced with `World::world_scope`
to avoid creating a new trait. This is a public facing change to the
call semantics, but has no effect on results or behaviour.
- `EntityMap`, as a `HashMap`, now operates on `&Entity` rather than
`Entity`. This changes many standard access functions (e.g, `.get`) in a
public-facing way.
## Migration Guide
- Calls to `EntityMap::world_scope` can be directly replaced with the
following:
`map.world_scope(&mut world)` -> `world.world_scope(&mut map)`
- Calls to legacy `EntityMap` methods such as `EntityMap::get` must
explicitly include de/reference symbols:
`let entity = map.get(parent);` -> `let &entity = map.get(&parent);`
# Objective
Similar to #6344, but contains only `ReflectBundle` changes. Useful for
scripting. The implementation has also been updated to look exactly like
`ReflectComponent`.
---
## Changelog
### Added
- Reflection for bundles.
---------
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Fix typos throughout the project.
## Solution
[`typos`](https://github.com/crate-ci/typos) project was used for
scanning, but no automatic corrections were applied. I checked
everything by hand before fixing.
Most of the changes are documentation/comments corrections. Also, there
are few trivial changes to code (variable name, pub(crate) function name
and a few error/panic messages).
## Unsolved
`bevy_reflect_derive` has
[typo](1b51053f19/crates/bevy_reflect/bevy_reflect_derive/src/type_path.rs (L76))
in enum variant name that I didn't fix. Enum is `pub(crate)`, so there
shouldn't be any trouble if fixed. However, code is tightly coupled with
macro usage, so I decided to leave it for more experienced contributor
just in case.
# Objective
**This implementation is based on
https://github.com/bevyengine/rfcs/pull/59.**
---
Resolves#4597
Full details and motivation can be found in the RFC, but here's a brief
summary.
`FromReflect` is a very powerful and important trait within the
reflection API. It allows Dynamic types (e.g., `DynamicList`, etc.) to
be formed into Real ones (e.g., `Vec<i32>`, etc.).
This mainly comes into play concerning deserialization, where the
reflection deserializers both return a `Box<dyn Reflect>` that almost
always contain one of these Dynamic representations of a Real type. To
convert this to our Real type, we need to use `FromReflect`.
It also sneaks up in other ways. For example, it's a required bound for
`T` in `Vec<T>` so that `Vec<T>` as a whole can be made `FromReflect`.
It's also required by all fields of an enum as it's used as part of the
`Reflect::apply` implementation.
So in other words, much like `GetTypeRegistration` and `Typed`, it is
very much a core reflection trait.
The problem is that it is not currently treated like a core trait and is
not automatically derived alongside `Reflect`. This makes using it a bit
cumbersome and easy to forget.
## Solution
Automatically derive `FromReflect` when deriving `Reflect`.
Users can then choose to opt-out if needed using the
`#[reflect(from_reflect = false)]` attribute.
```rust
#[derive(Reflect)]
struct Foo;
#[derive(Reflect)]
#[reflect(from_reflect = false)]
struct Bar;
fn test<T: FromReflect>(value: T) {}
test(Foo); // <-- OK
test(Bar); // <-- Panic! Bar does not implement trait `FromReflect`
```
#### `ReflectFromReflect`
This PR also automatically adds the `ReflectFromReflect` (introduced in
#6245) registration to the derived `GetTypeRegistration` impl— if the
type hasn't opted out of `FromReflect` of course.
<details>
<summary><h4>Improved Deserialization</h4></summary>
> **Warning**
> This section includes changes that have since been descoped from this
PR. They will likely be implemented again in a followup PR. I am mainly
leaving these details in for archival purposes, as well as for reference
when implementing this logic again.
And since we can do all the above, we might as well improve
deserialization. We can now choose to deserialize into a Dynamic type or
automatically convert it using `FromReflect` under the hood.
`[Un]TypedReflectDeserializer::new` will now perform the conversion and
return the `Box`'d Real type.
`[Un]TypedReflectDeserializer::new_dynamic` will work like what we have
now and simply return the `Box`'d Dynamic type.
```rust
// Returns the Real type
let reflect_deserializer = UntypedReflectDeserializer::new(®istry);
let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;
let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?;
// Returns the Dynamic type
let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry);
let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;
let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?;
```
</details>
---
## Changelog
* `FromReflect` is now automatically derived within the `Reflect` derive
macro
* This includes auto-registering `ReflectFromReflect` in the derived
`GetTypeRegistration` impl
* ~~Renamed `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` to
`TypedReflectDeserializer::new_dynamic` and
`UntypedReflectDeserializer::new_dynamic`, respectively~~ **Descoped**
* ~~Changed `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` to automatically convert the
deserialized output using `FromReflect`~~ **Descoped**
## Migration Guide
* `FromReflect` is now automatically derived within the `Reflect` derive
macro. Items with both derives will need to remove the `FromReflect`
one.
```rust
// OLD
#[derive(Reflect, FromReflect)]
struct Foo;
// NEW
#[derive(Reflect)]
struct Foo;
```
If using a manual implementation of `FromReflect` and the `Reflect`
derive, users will need to opt-out of the automatic implementation.
```rust
// OLD
#[derive(Reflect)]
struct Foo;
impl FromReflect for Foo {/* ... */}
// NEW
#[derive(Reflect)]
#[reflect(from_reflect = false)]
struct Foo;
impl FromReflect for Foo {/* ... */}
```
<details>
<summary><h4>Removed Migrations</h4></summary>
> **Warning**
> This section includes changes that have since been descoped from this
PR. They will likely be implemented again in a followup PR. I am mainly
leaving these details in for archival purposes, as well as for reference
when implementing this logic again.
* The reflect deserializers now perform a `FromReflect` conversion
internally. The expected output of `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` is no longer a Dynamic (e.g.,
`DynamicList`), but its Real counterpart (e.g., `Vec<i32>`).
```rust
let reflect_deserializer =
UntypedReflectDeserializer::new_dynamic(®istry);
let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;
// OLD
let output: DynamicStruct = reflect_deserializer.deserialize(&mut
deserializer)?.take()?;
// NEW
let output: SomeStruct = reflect_deserializer.deserialize(&mut
deserializer)?.take()?;
```
Alternatively, if this behavior isn't desired, use the
`TypedReflectDeserializer::new_dynamic` and
`UntypedReflectDeserializer::new_dynamic` methods instead:
```rust
// OLD
let reflect_deserializer = UntypedReflectDeserializer::new(®istry);
// NEW
let reflect_deserializer =
UntypedReflectDeserializer::new_dynamic(®istry);
```
</details>
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Use `AppTypeRegistry` on API defined in `bevy_ecs`
(https://github.com/bevyengine/bevy/pull/8895#discussion_r1234748418)
A lot of the API on `Reflect` depends on a registry. When it comes to
the ECS. We should use `AppTypeRegistry` in the general case.
This is however impossible in `bevy_ecs`, since `AppTypeRegistry` is
defined in `bevy_app`.
## Solution
- Move `AppTypeRegistry` resource definition from `bevy_app` to
`bevy_ecs`
- Still add the resource in the `App` plugin, since bevy_ecs itself
doesn't know of plugins
Note that `bevy_ecs` is a dependency of `bevy_app`, so nothing
revolutionary happens.
## Alternative
- Define the API as a trait in `bevy_app` over `bevy_ecs`. (though this
prevents us from using bevy_ecs internals)
- Do not rely on `AppTypeRegistry` for the API in question, requring
users to extract themselves the resource and pass it to the API methods.
---
## Changelog
- Moved `AppTypeRegistry` resource definition from `bevy_app` to
`bevy_ecs`
## Migration Guide
- If you were **not** using a `prelude::*` to import `AppTypeRegistry`,
you should update your imports:
```diff
- use bevy::app::AppTypeRegistry;
+ use bevy::ecs::reflect::AppTypeRegistry
```
