Commit graph

1310 commits

Author SHA1 Message Date
Thomas Alban
e4b740840f
Add filter_map_unchanged to Mut<T> (#14837)
Closes #14836.

`filter_map_unchanged` optionally maps to an inner value by applying a
function to the contained reference. This is useful in a situation where
you need to convert a `Mut<T>` to a `Mut<U>`, but only if `T` contains
`U`.

---------

Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
2024-08-22 17:51:21 +00:00
EdJoPaTo
938d810766
Apply unused_qualifications lint (#14828)
# Objective

Fixes #14782

## Solution

Enable the lint and fix all upcoming hints (`--fix`). Also tried to
figure out the false-positive (see review comment). Maybe split this PR
up into multiple parts where only the last one enables the lint, so some
can already be merged resulting in less many files touched / less
potential for merge conflicts?

Currently, there are some cases where it might be easier to read the
code with the qualifier, so perhaps remove the import of it and adapt
its cases? In the current stage it's just a plain adoption of the
suggestions in order to have a base to discuss.

## Testing

`cargo clippy` and `cargo run -p ci` are happy.
2024-08-21 12:29:33 +00:00
Periwink
eaa805102d
add docs explaining the two accesses of a System meta (#14580)
# Objective

When reading the ECS code it is sometimes confusing to understand why we
have 2 accesses, one of ComponentId and one of ArchetypeComponentId


## Solution

Make the usage of these 2 accesses more explicit

---------

Co-authored-by: Pascal Hertleif <killercup@gmail.com>
2024-08-19 21:32:45 +00:00
Luca Della Vedova
6d3b2faf8a
Fix commands not being Send / Sync in 0.14 (#14392)
# Objective

Fixes Commands not being `Send` or `Sync` anymore in 0.14 by
implementing `Send` and `Sync` for `RawCommandQueue`.

## Solution

Reference discussion in
[discord](https://discord.com/channels/691052431525675048/691052431974465548/1259464518539411570).
It seems that in https://github.com/bevyengine/bevy/pull/13249, when
adding a `RawCommandQueue` variant to the `InternalQueue`, the `Send /
Sync` traits were not implemented for it, which bubbled up all the way
to `Commands` not being `Send / Sync` anymore.
I am not very familiar with the ECS internals so I can't say whether the
`RawCommandQueue` is safe to be shared between threads, but I know for
sure that before the linked PR `Commands` were indeed `Send` and `Sync`
so that PR broke "some workflows" (mandatory
[xkcd](https://xkcd.com/1172/)).

## Testing

This PR itself includes a compile test to make sure `Commands` will
implement `Send` and `Sync`. The test itself fails without the
implementation and succeeds with it.
Furthermore, if I cherry pick the test to a previous release (i.e. 0.13)
it indeed succeeds, showing that this is a regression specific to 0.14.

---------

Signed-off-by: Luca Della Vedova <lucadv@intrinsic.ai>
2024-08-19 21:29:30 +00:00
nsarlin
313db39912
Add try_insert_with_new (#14787)
# Objective
Fix #14771 by adding a `try_insert_if_new` method to the
`EntityCommands`

## Solution
This simply calls the  `try_insert` function with `InsertMode::Keep`

## Testing
I did not add any test because `EntityCommands::try_insert` does not
seem to be tested either. I can add some if needed.
2024-08-16 21:25:11 +00:00
Jeff Petkau
b2529bf100
feat: add insert_if_new (#14397) (#14646)
# Objective

Often there are reasons to insert some components (e.g. Transform)
separately from the rest of a bundle (e.g. PbrBundle). However `insert`
overwrites existing components, making this difficult.

See also issue #14397

Fixes #2054.

## Solution

This PR adds the method `insert_if_new` to EntityMut and Commands, which
is the same as `insert` except that the old component is kept in case of
conflicts.

It also renames some internal enums (from `ComponentStatus::Mutated` to
`Existing`), to reflect the possible change in meaning.

## Testing

*Did you test these changes? If so, how?*

Added basic unit tests; used the new behavior in my project.

*Are there any parts that need more testing?*

There should be a test that the change time isn't set if a component is
not overwritten; I wasn't sure how to write a test for that case.

*How can other people (reviewers) test your changes? Is there anything
specific they need to know?*

`cargo test` in the bevy_ecs project.

*If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?*

Only tested on Windows, but it doesn't touch anything platform-specific.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com>
2024-08-15 20:31:41 +00:00
Giacomo Stevanato
e9e9e5e15d
Add query reborrowing (#14690)
# Objective

- Sometimes some method or function takes an owned `Query`, but we don't
want to give up ours;
- transmuting it technically a solution, but it more costly than
necessary.
- Make query iterators more flexible
- this would allow the equivalent of
`slice::split_first`/`slice::split_first_mut` for query iterators
  - helps with requests like #14685

## Solution

- Add a way for reborrowing queries, that is going from a `&'a mut
Query<'w, 's, D, F>` to a `Query<'a, 's, D, F>`:
- this is safe because the original query will be borrowed while the new
query exists and thus no aliased access can happen;
- it's basically the equivalent of going from `&'short mut &'long mut T`
to `&'short mut T` the the compiler automatically implements.
- Add a way for getting the remainder of a query iterator:
- this is interesting also because the original iterator keeps its
position, which was not possible before;
- this in turn requires a way to reborrow query fetches, which I had to
add to `WorldQuery`.

## Showcase

- You can now reborrow a `Query`, getting an equivalent `Query` with a
shorter lifetime. Previously this was possible for read-only queries by
using `Query::to_readonly`, now it's possible for mutable queries too;
- You can now separately iterate over the remainder of `QueryIter`.

## Migration Guide

- `WorldQuery` now has an additional `shrink_fetch` method you have to
implement if you were implementing `WorldQuery` manually.
2024-08-15 17:38:56 +00:00
Chris Russell
340c749d16
Remove redundant ArchetypeComponentId lookup in Res and ResMut (#14691)
# Objective

`Res` and `ResMut` perform redundant lookups of the resource storage,
first to initialize the `ArchetypeComponentId` and then to retrieve it.

## Solution

Use the `archetype_component_id` returned from
`initialize_resource_internal` to avoid an extra lookup and `unwrap()`.
2024-08-15 16:12:03 +00:00
Chris Russell
0ea46663b0
Use map_unchanged in reflection instead of creating a Mut manually. (#14692)
# 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>
2024-08-15 14:26:57 +00:00
Ben Frankel
d849941dac
Add entity .trigger() methods (#14752)
# Objective

Fix https://github.com/bevyengine/bevy/issues/14233.

## Solution

Add `EntityCommands::trigger` and `EntityWorldMut::trigger`.

## Testing

- Not tested.
2024-08-15 14:16:06 +00:00
re0312
3bd039e821
Skip empty archetype/table (#14749)
# Objective

- As sander commneted on discord
[link](https://discord.com/channels/691052431525675048/749335865876021248/1273414144091230228),

![image](https://github.com/user-attachments/assets/62f2b6f3-1aaf-49d9-bafa-bf62b83b10be)





## Performance

![image](https://github.com/user-attachments/assets/11122940-1547-42ae-9576-0e1a93fd9f5f)

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com>
2024-08-15 14:07:20 +00:00
Ben Frankel
6da2305e49
Add Command and co. to prelude (#14751)
# Objective

Make it easier to write and work with custom `Command`s and
`EntityCommand`s. See
https://discord.com/channels/691052431525675048/692572690833473578/1273030340235100214
for (brief) context.

## Solution

Re-export `Command`, `EntityCommand`, and `EntityCommands` in the
`bevy_ecs::prelude`, where `Commands` is already re-exported.
2024-08-15 13:33:32 +00:00
Christian Hughes
7d3068e6c3
Fix world borrow for DeferredWorld::query (#14744)
# Objective

As is, calling
[`DeferredWorld::query`](https://docs.rs/bevy/latest/bevy/ecs/world/struct.DeferredWorld.html#method.query)
requires you to first `reborrow()` the world in order to use it at all.

Simple reproduction:
```rust
fn test<'w>(mut world: DeferredWorld<'w>, mut state: QueryState<(), ()>) {
    let query = world.query(&mut state);
    // let query = world.reborrow().query(&mut state); // << Required
}
```

Error message:
```
error[E0597]: `world` does not live long enough
    |
444 | fn test<'w>(mut world: DeferredWorld<'w>, mut state: QueryState<(), ()>) {
    |         --  --------- binding `world` declared here
    |         |
    |         lifetime `'w` defined here
445 |     let query = world.query(&mut state);
    |                 ^^^^^------------------
    |                 |
    |                 borrowed value does not live long enough
    |                 argument requires that `world` is borrowed for `'w`
446 | }
    |  - `world` dropped here while still borrowed

```

## Solution

Fix the world borrow lifetime on the `query` method, which now correctly
allows the above usage.
2024-08-14 18:59:19 +00:00
Tau Gärtli
aab1f8e435
Use #[doc(fake_variadic)] to improve docs readability (#14703)
# Objective

- Fixes #14697

## Solution

This PR modifies the existing `all_tuples!` macro to optionally accept a
`#[doc(fake_variadic)]` attribute in its input. If the attribute is
present, each invocation of the impl macro gets the correct attributes
(i.e. the first impl receives `#[doc(fake_variadic)]` while the other
impls are hidden using `#[doc(hidden)]`.
Impls for the empty tuple (unit type) are left untouched (that's what
the [standard
library](https://doc.rust-lang.org/std/cmp/trait.PartialEq.html#impl-PartialEq-for-())
and
[serde](https://docs.rs/serde/latest/serde/trait.Serialize.html#impl-Serialize-for-())
do).

To work around https://github.com/rust-lang/cargo/issues/8811 and to get
impls on re-exports to correctly show up as variadic, `--cfg docsrs_dep`
is passed when building the docs for the toplevel `bevy` crate.

`#[doc(fake_variadic)]` only works on tuples and fn pointers, so impls
for structs like `AnyOf<(T1, T2, ..., Tn)>` are unchanged.

## Testing

I built the docs locally using `RUSTDOCFLAGS='--cfg docsrs'
RUSTFLAGS='--cfg docsrs_dep' cargo +nightly doc --no-deps --workspace`
and checked the documentation page of a trait both in its original crate
and the re-exported version in `bevy`.
The description should correctly mention for how many tuple items the
trait is implemented.

I added `rustc-args` for docs.rs to the `bevy` crate, I hope there
aren't any other notable crates that re-export `#[doc(fake_variadic)]`
traits.

---

## Showcase

`bevy_ecs::query::QueryData`:
<img width="1015" alt="Screenshot 2024-08-12 at 16 41 28"
src="https://github.com/user-attachments/assets/d40136ed-6731-475f-91a0-9df255cd24e3">

`bevy::ecs::query::QueryData` (re-export):
<img width="1005" alt="Screenshot 2024-08-12 at 16 42 57"
src="https://github.com/user-attachments/assets/71d44cf0-0ab0-48b0-9a51-5ce332594e12">

## Original Description

<details>

Resolves #14697

Submitting as a draft for now, very WIP.

Unfortunately, the docs don't show the variadics nicely when looking at
reexported items.
For example:

`bevy_ecs::bundle::Bundle` correctly shows the variadic impl:

![image](https://github.com/user-attachments/assets/90bf8af1-1d1f-4714-9143-cdd3d0199998)

while `bevy::ecs::bundle::Bundle` (the reexport) shows all the impls
(not good):

![image](https://github.com/user-attachments/assets/439c428e-f712-465b-bec2-481f7bf5870b)

Built using `RUSTDOCFLAGS='--cfg docsrs' cargo +nightly doc --workspace
--no-deps` (`--no-deps` because of wgpu-core).

Maybe I missed something or this is a limitation in the *totally not
private* `#[doc(fake_variadic)]` thingy. In any case I desperately need
some sleep now :))

</details>
2024-08-12 18:54:33 +00:00
radiish
6ab8767d3b
reflect: implement the unique reflect rfc (#7207)
# 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>
2024-08-12 17:01:41 +00:00
databasedav
c8d30edf1a
add SystemIdMarker Component to enable filtering for SystemId Entitys (#14584)
# Objective

Enables writing queries like `Query<Entity, With<SystemIdMarker>>` to
filter `Entity`s that are, or are not (with `Without`), `SystemId`s.

## Solution

Simple unit struct `SystemIdMarker` added during
`World::register_boxed_system`; `World::remove_system` already despawns
the entity, removing the marker.

## Testing

No tests, but happy to write some with direction.

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-08-12 16:11:06 +00:00
databasedav
c3111bebb8
document using ObserverState as filter for Observer Entitys (#14669)
# Objective

~~Enables writing queries like `Query<Entity, With<ObserverMarker>>` to
filter `Entity`s that are, or are not (with `Without`), `Observer`s.~~

~~`Observer` version of [similar
PR](https://github.com/bevyengine/bevy/pull/14584) for `SystemId`s.~~

just adding a line to the docs :)

## Solution

~~Simple unit struct `ObserverMarker` added in `Observer`'s `.on_add`
component hook.~~

## Testing

No tests, but happy to write some with direction.
2024-08-12 16:07:03 +00:00
Chris Russell
d4ec80d5d2
Support more kinds of system params in buildable systems. (#14050)
# Objective

Support more kinds of system params in buildable systems, such as a
`ParamSet` or `Vec` containing buildable params or tuples of buildable
params.

## Solution

Replace the `BuildableSystemParam` trait with `SystemParamBuilder` to
make it easier to compose builders. Provide implementations for existing
buildable params, plus tuples, `ParamSet`, and `Vec`.

## Examples

```rust
// ParamSet of tuple: 
let system = (ParamSetBuilder((
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new(|builder| { builder.with::<C>(); }),
)),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<(Query<&mut A>, Query<&mut A>)>| {
        params.p0().iter().count() + params.p1().iter().count()
    });
	
// ParamSet of Vec:
let system = (ParamSetBuilder(vec![
    QueryParamBuilder::new_box(|builder| { builder.with::<B>(); }),
    QueryParamBuilder::new_box(|builder| { builder.with::<C>(); }),
]),)
    .build_state(&mut world)
    .build_system(|mut params: ParamSet<Vec<Query<&mut A>>>| {
        let mut count = 0;
        params.for_each(|mut query| count += query.iter_mut().count());
        count
    });
```

## Migration Guide

The API for `SystemBuilder` has changed. Instead of constructing a
builder with a world and then adding params, you first create a tuple of
param builders and then supply the world.

```rust
// Before
let system = SystemBuilder::<()>::new(&mut world)
    .local::<u64>()
    .builder::<Local<u64>>(|x| *x = 10)
    .builder::<Query<&A>>(|builder| { builder.with::<B>(); })
    .build(system);

// After
let system = (
    ParamBuilder,
    LocalBuilder(10),
    QueryParamBuilder::new(|builder| { builder.with::<B>(); }),
)
    .build_state(&mut world)
    .build_system(system);
```

## Possible Future Work

Here are a few possible follow-up changes. I coded them up to prove that
this API can support them, but they aren't necessary for this PR.

* chescock/bevy#1
* chescock/bevy#2
* chescock/bevy#3
2024-08-12 15:45:35 +00:00
Christian Hughes
7f658cabf7
Replace UnsafeCell<World> usage with UnsafeWorldCell in CombinatorSystem (#14706)
# Objective

Replace usage of `UnsafeCell<World>` with our standard `UnsafeWorldCell`
that seemed to have been missed.

## Solution

Do just that.
2024-08-11 13:58:10 +00:00
re0312
e490b919df
inline iter_combinations (#14680)
# Objective
- fix #14679 
- bevy's performance highly depends on compiler optimization,inline hot
function could greatly help compiler to optimize our program
2024-08-09 17:44:37 +00:00
re0312
66bf160ec5
Explicit using clone_from (#14670)
# Objective

- after #14502 ,explicit using clone_from should has better performance
because it could reuse the resources to avoid unnecessary allocations.
2024-08-09 14:17:13 +00:00
eckz
8c2e70b744
Adding Reflect data types for States and FreelyMutableState. (#14643)
# 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>
2024-08-08 00:07:00 +00:00
Periwink
2334638556
Fix access conflicts for resources (#14635)
# Objective

- I made a mistake when fixing the merge conflicts here:
https://github.com/bevyengine/bevy/pull/14579#discussion_r1705377452

It wasn't caught because there's no easy way to trigger access conflicts
with resources without triggering them with components first.
2024-08-06 14:35:41 +00:00
Periwink
e85c072372
Fix soudness issue with Conflicts involving read_all and write_all (#14579)
# Objective

- Fixes https://github.com/bevyengine/bevy/issues/14575
- There is a soundness issue because we use `conflicts()` to check for
system ambiguities + soundness issues. However since the current
conflicts is a `Vec<T>`, we cannot express conflicts where there is no
specific `ComponentId` at fault. For example `q1: Query<EntityMut>, q2:
Query<EntityMut>`
There was a TODO to handle the `write_all` case but it was never
resolved


## Solution

- Introduce an `AccessConflict` enum that is either a list of specific
ids that are conflicting or `All` if all component ids are conflicting

## Testing

- Introduced a new unit test to check for the `EntityMut` case

## Migration guide

The `get_conflicts` method of `Access` now returns an `AccessConflict`
enum instead of simply a `Vec` of `ComponentId`s that are causing the
access conflict. This can be useful in cases where there are no
particular `ComponentId`s conflicting, but instead **all** of them are;
for example `fn system(q1: Query<EntityMut>, q2: Query<EntityRef>)`
2024-08-06 10:55:31 +00:00
Lubba64
897625c899
Add Reflect to OnReplace (#14620)
# Objective

- Fixes #14337 

## Solution

- Add a `cfg_attr` that derives `Refect` for this type. 

## Testing

- I am going to make sure the tests pass on this PR before requesting
review, If more testing is necessary let me know some good action steps
to take.
2024-08-06 01:31:13 +00:00
Periwink
3a664b052d
Separate component and resource access (#14561)
# Objective

- Fixes https://github.com/bevyengine/bevy/issues/13139
- Fixes https://github.com/bevyengine/bevy/issues/7255
- Separates component from resource access so that we can correctly
handles edge cases like the issue above
- Inspired from https://github.com/bevyengine/bevy/pull/14472

## Solution

- Update access to have `component` fields and `resource` fields

## Testing

- Added some unit tests
2024-08-06 01:19:39 +00:00
Gino Valente
df61117850
bevy_reflect: Function registry (#14098)
# 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.
2024-08-06 01:09:48 +00:00
Periwink
ec4cf024f8
Add a ComponentIndex and update QueryState creation/update to use it (#13460)
# Objective

To implement relations we will need to add a `ComponentIndex`, which is
a map from a Component to the list of archetypes that contain this
component.
One of the reasons is that with fragmenting relations the number of
archetypes will explode, so it will become inefficient to create and
update the query caches by iterating through the list of all archetypes.

In this PR, we introduce the `ComponentIndex`, and we update the
`QueryState` to make use of it:
- if a query has at least 1 required component (i.e. something other
than `()`, `Entity` or `Option<>`, etc.): for each of the required
components we find the list of archetypes that contain it (using the
ComponentIndex). Then, we select the smallest list among these. This
gives a small subset of archetypes to iterate through compared with
iterating through all new archetypes
- if it doesn't, then we keep using the current approach of iterating
through all new archetypes


# Implementation
- This breaks query iteration order, in the sense that we are not
guaranteed anymore to return results in the order in which the
archetypes were created. I think this should be fine because this wasn't
an explicit bevy guarantee so users should not be relying on this. I
updated a bunch of unit tests that were failing because of this.

- I had an issue with the borrow checker because iterating the list of
potential archetypes requires access to `&state.component_access`, which
was conflicting with the calls to
```
  if state.new_archetype_internal(archetype) {
      state.update_archetype_component_access(archetype, access);
  }
```
which need a mutable access to the state.

The solution I chose was to introduce a `QueryStateView` which is a
temporary view into the `QueryState` which enables a "split-borrows"
kind of approach. It is described in detail in this blog post:
https://smallcultfollowing.com/babysteps/blog/2018/11/01/after-nll-interprocedural-conflicts/

# Test

The unit tests pass.

Benchmark results:
```
❯ critcmp main pr
group                                  main                                   pr
-----                                  ----                                   --
iter_fragmented/base                   1.00   342.2±25.45ns        ? ?/sec    1.02   347.5±16.24ns        ? ?/sec
iter_fragmented/foreach                1.04   165.4±11.29ns        ? ?/sec    1.00    159.5±4.27ns        ? ?/sec
iter_fragmented/foreach_wide           1.03      3.3±0.04µs        ? ?/sec    1.00      3.2±0.06µs        ? ?/sec
iter_fragmented/wide                   1.03      3.1±0.06µs        ? ?/sec    1.00      3.0±0.08µs        ? ?/sec
iter_fragmented_sparse/base            1.00      6.5±0.14ns        ? ?/sec    1.02      6.6±0.08ns        ? ?/sec
iter_fragmented_sparse/foreach         1.00      6.3±0.08ns        ? ?/sec    1.04      6.6±0.08ns        ? ?/sec
iter_fragmented_sparse/foreach_wide    1.00     43.8±0.15ns        ? ?/sec    1.02     44.6±0.53ns        ? ?/sec
iter_fragmented_sparse/wide            1.00     29.8±0.44ns        ? ?/sec    1.00     29.8±0.26ns        ? ?/sec
iter_simple/base                       1.00      8.2±0.10µs        ? ?/sec    1.00      8.2±0.09µs        ? ?/sec
iter_simple/foreach                    1.00      3.8±0.02µs        ? ?/sec    1.02      3.9±0.03µs        ? ?/sec
iter_simple/foreach_sparse_set         1.00     19.0±0.26µs        ? ?/sec    1.01     19.3±0.16µs        ? ?/sec
iter_simple/foreach_wide               1.00     17.8±0.24µs        ? ?/sec    1.00     17.9±0.31µs        ? ?/sec
iter_simple/foreach_wide_sparse_set    1.06     95.6±6.23µs        ? ?/sec    1.00     90.6±0.59µs        ? ?/sec
iter_simple/sparse_set                 1.00     19.3±1.63µs        ? ?/sec    1.01     19.5±0.29µs        ? ?/sec
iter_simple/system                     1.00      8.1±0.10µs        ? ?/sec    1.00      8.1±0.09µs        ? ?/sec
iter_simple/wide                       1.05     37.7±2.53µs        ? ?/sec    1.00     35.8±0.57µs        ? ?/sec
iter_simple/wide_sparse_set            1.00     95.7±1.62µs        ? ?/sec    1.00     95.9±0.76µs        ? ?/sec
par_iter_simple/with_0_fragment        1.04     35.0±2.51µs        ? ?/sec    1.00     33.7±0.49µs        ? ?/sec
par_iter_simple/with_1000_fragment     1.00     50.4±2.52µs        ? ?/sec    1.01     51.0±3.84µs        ? ?/sec
par_iter_simple/with_100_fragment      1.02     40.3±2.23µs        ? ?/sec    1.00     39.5±1.32µs        ? ?/sec
par_iter_simple/with_10_fragment       1.14     38.8±7.79µs        ? ?/sec    1.00     34.0±0.78µs        ? ?/sec
```
2024-08-06 00:57:15 +00:00
Giacomo Stevanato
68ec6f4f50
Make QueryState::transmute&co validate the world of the &Components used (#14631)
# Objective

- Fix #14629

## Solution

- Make `QueryState::transmute`, `QueryState::transmute_filtered`,
`QueryState::join` and `QueryState::join_filtered` take a `impl
Into<UnsafeWorldCell>` instead of a `&Components` and validate their
`WorldId`

## Migration Guide

- `QueryState::transmute`, `QueryState::transmute_filtered`,
`QueryState::join` and `QueryState::join_filtered` now take a `impl
Into<UnsafeWorldCell>` instead of a `&Components`

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-08-05 22:39:31 +00:00
re0312
8235daaea0
Opportunistically use dense iteration for archetypal iteration (#14049)
# Objective
- currently, bevy employs sparse iteration if any of the target
components in the query are stored in a sparse set. it may lead to
increased cache misses in some cases, potentially impacting performance.
- partial fixes #12381 

## Solution

- use dense iteration when an archetype and its table have the same
entity count.
- to avoid introducing complicate unsafe noise, this pr only implement
for `for_each ` style iteration.
- added a benchmark to test performance for hybrid iteration.


## Performance


![image](https://github.com/bevyengine/bevy/assets/45868716/5cce13cf-6ff2-4861-9576-e75edc63bd46)

nearly 2x win in specific scenarios, and no performance degradation in
other test cases.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com>
2024-08-02 21:18:15 +00:00
SpecificProtagonist
0685d2da4d
B0003: Print caller (#14556)
# Objective

B0003 indicates that you tried to act upon a nonexistant entity, but
does not mention where the error occured:
```
2024-07-31T15:46:25.954840Z  WARN bevy_ecs::world: error[B0003]: Could not despawn entity Entity { index: 4294967295, generation: 1 } because it doesn't exist in this World. See: https://bevyengine.org/learn/errors/b0003
```

## Solution

Include caller location:

```
2024-07-31T15:46:25.954840Z  WARN bevy_ecs::world: error[B0003]: src/main.rs:18:11: Could not despawn entity Entity { index: 4294967295, generation: 1 } because it doesn't exist in this World. See: https://bevyengine.org/learn/errors/b0003
```

Open question: What should the exact message format be?

## Testing

None, this doesn't change any logic.
2024-08-01 00:14:48 +00:00
Jan Hohenheim
6f7c554daa
Fix common capitalization errors in documentation (#14562)
WASM -> Wasm
MacOS -> macOS

Nothing important, just something that annoyed me for a while :)
2024-07-31 21:16:05 +00:00
Zeenobit
023e0e5bde
Fix Entity Debug Format (#14539)
# Objective

Fixes #12139

## Solution

See this comment on original issue for my proposal:
https://github.com/bevyengine/bevy/issues/12139#issuecomment-2241915791

This PR is an implementation of this proposal.

I modified the implementation of `fmt::Debug` to instead display
`0v0#12345` to ensure entity index, generation, and raw bits are all
present in the output for debug purposes while still keeping log message
concise.

`fmt::Display` remains as is (`0v0`) to offer an even shorter output.

To me, this is the most non-intrusive fix for this issue.

## Testing

Add `fn entity_debug` test

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2024-07-31 01:36:41 +00:00
BD103
399219a2c7
Fix rust beta lints (#14537)
# Objective

- Fixes #14517.

## Solution

- Replace two instances of `map()` with `inspect()`.
- `#[allow(dead_code)]` on `Bundle` derive macro tests.

## Testing

You need to install the beta toolchain, since these lints are not stable
yet.

```bash
cargo +beta clippy --workspace
cargo +beta test --workspace
```
2024-07-31 01:27:26 +00:00
Aevyrie
9575b20d31
Track source location in change detection (#14034)
# 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>
2024-07-30 12:02:38 +00:00
Rostyslav Toch
455c1bfbe8
Optimize cloning for Access-related structs (#14502)
# Objective

Optimize the cloning process for Access-related structs in the ECS
system, specifically targeting the `clone_from` method.

Previously, profiling showed that 1% of CPU time was spent in
`FixedBitSet`'s `drop_in_place`, due to the default `clone_from`
implementation:

```rust
fn clone_from(&mut self, source: &Self) {
    *self = source.clone()
}
```

This implementation causes unnecessary allocations and deallocations.
However, [FixedBitSet provides a more optimized clone_from
method](https://github.com/petgraph/fixedbitset/blob/master/src/lib.rs#L1445-L1465)
that avoids these allocations and utilizes SIMD instructions for better
performance.

This PR aims to leverage the optimized clone_from method of FixedBitSet
and implement custom clone_from methods for Access-related structs to
take full advantage of this optimization. By doing so, we expect to
significantly reduce CPU time spent on cloning operations and improve
overall system performance.



![image](https://github.com/user-attachments/assets/7526a5c5-c75b-4a9a-b8d2-891f64fd553b)


## Solution

- Implemented custom `clone` and `clone_from` methods for `Access`,
`FilteredAccess`, `AccessFilters`, and `FilteredAccessSet` structs.
- Removed `#[derive(Clone)]` and manually implemented `Clone` trait to
use optimized `clone_from` method from `FixedBitSet`.
- Added unit tests for cloning and `clone_from` methods to ensure
correctness.

## Testing

- Conducted performance testing comparing the original and optimized
versions.
- Measured CPU time consumption for the `clone_from` method:
  - Original version: 1.34% of CPU time
  - Optimized version: 0.338% of CPU time
- Compared FPS before and after the changes (results may vary depending
on the run):

Before optimization:
```
2024-07-28T12:49:11.864019Z  INFO bevy diagnostic: fps        :  213.489463   (avg 214.502488)
2024-07-28T12:49:11.864037Z  INFO bevy diagnostic: frame_time :    4.704746ms (avg 4.682251ms)
2024-07-28T12:49:11.864042Z  INFO bevy diagnostic: frame_count: 7947.000000   (avg 7887.500000)
```


![image](https://github.com/user-attachments/assets/7865a365-0569-4b46-814a-964779d90973)

After optimization:
```
2024-07-28T12:29:42.705738Z  INFO bevy diagnostic: fps        :  220.273721   (avg 220.912227)
2024-07-28T12:29:42.705762Z  INFO bevy diagnostic: frame_time :    4.559127ms (avg 4.544905ms)
2024-07-28T12:29:42.705769Z  INFO bevy diagnostic: frame_count: 7596.000000   (avg 7536.500000)
```


![image](https://github.com/user-attachments/assets/8dd96908-86d0-4850-8e29-f80176a005d6)

---

Reviewers can test these changes by running `cargo run --release
--example ssr`
2024-07-29 23:48:21 +00:00
Giacomo Stevanato
7de271f992
Add FilteredAccess::empty and simplify the implementatin of update_component_access for AnyOf/Or (#14352)
# Objective

- The implementation of `update_component_access` for `AnyOf`/`Or` is
kinda weird due to special casing the first filter, let's simplify it;
- Fundamentally we want to fold/reduce the various filters using an OR
operation, however in order to do a proper fold we need a neutral
element for the initial accumulator, which for OR is FALSE. However we
didn't have a way to create a `FilteredAccess` value corresponding to
FALSE and thus the only option was reducing, which special cases the
first element as being the initial accumulator.

This is an alternative to https://github.com/bevyengine/bevy/pull/14026

## Solution

- Introduce `FilteredAccess::empty` as a way to create a
`FilteredAccess` corresponding to the logical proposition FALSE;
- Use it as the initial accumulator for the above operations, allowing
to handle all the elements to fold in the same way.

---

## Migration Guide

- The behaviour of `AnyOf<()>` and `Or<()>` has been changed to match no
archetypes rather than all archetypes to naturally match the
corresponding logical operation. Consider replacing them with `()`
instead.
2024-07-29 23:20:06 +00:00
Giacomo Stevanato
bc80b95257
Don't debug SystemId's entity field twice (#14499)
# Objective

- `SystemId`'s `Debug` implementation includes its `entity` field twice.
- This was likely an oversight in #11019, since before that PR the
second field was the `PhantomData` one.

## Solution

- Only include it once

Alternatively, this could be changed to match the struct representation
of `SystemId`, thus instructing the formatter to print a named struct
and including the `PhantomData` field.
2024-07-27 16:15:39 +00:00
thatchedroof
4f5b8ca08c
Fix typo in World::observe (#14492)
# Objective

- Fix a typo in the documentation for `World::observe`

## Solution

- Change `Spawn` to `Spawns` and `it's` to `its`
2024-07-27 13:55:44 +00:00
Dmytro Banin
e9e29d61c6
Add intradoc links for observer triggers (#14458)
# Objective

When using observers you might want to know what the difference is
between `OnAdd` vs `OnReplace` vs `OnInsert` etc. It's not obvious where
to look (`component_hooks.rs`). Added intradoc links for easier
disambiguation.
2024-07-24 18:41:23 +00:00
Joseph
218f78157d
Require &mut self for World::increment_change_tick (#14459)
# Objective

The method `World::increment_change_tick` currently takes `&self` as the
method receiver, which is semantically strange. Even though the interior
mutability is sound, the existence of this method is strange since we
tend to think of `&World` as being a read-only snapshot of a world, not
an aliasable reference to a world with mutability. For those purposes,
we have `UnsafeWorldCell`.

## Solution

Change the method signature to take `&mut self`. Use exclusive access to
remove the need for atomic adds, which makes the method slightly more
efficient. Redirect users to [`UnsafeWorldCell::increment_change_tick`]
if they need to increment the world's change tick from an aliased
context.

In practice I don't think there will be many breakages, if any. In cases
where you need to call `increment_change_tick`, you usually already have
either `&mut World` or `UnsafeWorldCell`.

---

## Migration Guide

The method `World::increment_change_tick` now requires `&mut self`
instead of `&self`. If you need to call this method but do not have
mutable access to the world, consider using
`world.as_unsafe_world_cell_readonly().increment_change_tick()`, which
does the same thing, but is less efficient than the method on `World`
due to requiring atomic synchronization.

```rust
fn my_system(world: &World) {
    // Before
    world.increment_change_tick();

    // After
    world.as_unsafe_world_cell_readonly().increment_change_tick();
}
```
2024-07-24 12:42:28 +00:00
Felix Rath
abceebebba
feat: Add World::get_reflect() and World::get_reflect_mut() (#14416)
# Objective

Sometimes one wants to retrieve a `&dyn Reflect` for an entity's
component, which so far required multiple, non-obvious steps and
`unsafe`-code.
The docs for
[`MutUntyped`](https://docs.rs/bevy/latest/bevy/ecs/change_detection/struct.MutUntyped.html#method.map_unchanged)
contain an example of the unsafe part.

## Solution

This PR adds the two methods:

```rust
// immutable variant
World::get_reflect(&self, entity: Entity, type_id: TypeId) -> Result<&dyn Reflect, GetComponentReflectError>

// mutable variant
World::get_reflect_mut(&mut self, entity: Entity, type_id: TypeId) -> Result<Mut<'_, dyn Reflect>, GetComponentReflectError>
```

which take care of the necessary steps, check required invariants etc.,
and contain the unsafety so the caller doesn't have to deal with it.

## Testing

- Did you test these changes? If so, how?
- Added tests and a doc test, also (successfully) ran `cargo run -p ci`.
- Are there any parts that need more testing?
- Could add tests for each individual error variant, but it's not
required imo.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Run `cargo test --doc --package bevy_ecs --all-features --
world::World::get_reflect --show-output` for the doctest
- Run `cargo test --package bevy_ecs --lib --all-features --
world::tests::reflect_tests --show-output` for the unittests
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
  - Don't think it's relevant, but tested on 64bit linux (only).

---

## Showcase

Copy of the doctest example which gives a good overview of what this
enables:

```rust
use bevy_ecs::prelude::*;
use bevy_reflect::Reflect;
use std::any::TypeId;

// define a `Component` and derive `Reflect` for it
#[derive(Component, Reflect)]
struct MyComponent;

// create a `World` for this example
let mut world = World::new();

// Note: This is usually handled by `App::register_type()`, but this example can not use `App`.
world.init_resource::<AppTypeRegistry>();
world.get_resource_mut::<AppTypeRegistry>().unwrap().write().register::<MyComponent>();

// spawn an entity with a `MyComponent`
let entity = world.spawn(MyComponent).id();

// retrieve a reflected reference to the entity's `MyComponent`
let comp_reflected: &dyn Reflect = world.get_reflect(entity, TypeId::of::<MyComponent>()).unwrap();

// make sure we got the expected type
assert!(comp_reflected.is::<MyComponent>());
```

## Migration Guide

No breaking changes, but users can use the new methods if they did it
manually before.

---------

Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2024-07-23 16:57:54 +00:00
Ben Frankel
ee88d79d88
Simplify run conditions (#14441)
# Objective

Simplify Bevy-provided functions that return a condition-satisfying
closure instead of just being the condition.

## Solution

Become the condition.

## Testing

I did not test. Game jamming. Hopefully CI passes.

---

## Migration Guide

Some run conditions have been simplified.

```rust
// Before:
app.add_systems(Update, (
    system_0.run_if(run_once()),
    system_1.run_if(resource_changed_or_removed::<T>()),
    system_2.run_if(resource_removed::<T>()),
    system_3.run_if(on_event::<T>()),
    system_4.run_if(any_component_removed::<T>()),
));

// After:
app.add_systems(Update, (
    system_0.run_if(run_once),
    system_1.run_if(resource_changed_or_removed::<T>),
    system_2.run_if(resource_removed::<T>),
    system_3.run_if(on_event::<T>),
    system_4.run_if(any_component_removed::<T>),
));
```
2024-07-22 19:21:47 +00:00
Peter Hayman
b8416b3043
Add some missing reflect attributes (#14259)
# Objective

- Some types are missing reflection attributes, which means we can't use
them in scene serialization etc.
- Effected types
   - `BorderRadius`
   - `AnimationTransitions`
   - `OnAdd`
   - `OnInsert`
   - `OnRemove`
- My use-case for `OnAdd` etc to derive reflect is 'Serializable
Observer Components'. Add the component, save the scene, then the
observer is re-added on scene load.

```rust
#[derive(Reflect)]
struct MySerializeableObserver<T: Event>(#[reflect(ignore)]PhantomData<T>);

impl<T: Event> Component for MySerializeableObserver<T> {
  const STORAGE_TYPE: StorageType  = StorageType::Table;
    fn register_component_hooks(hooks: &mut ComponentHooks) {
      hooks.on_add(|mut world, entity, _| {
        world
          .commands()
          .entity(entity)
          .observe(|_trigger: Trigger<T>| {
            println!("it triggered etc.");
          });
    });
  }
}
```

## Solution

- Add the missing traits

---
2024-07-22 18:24:10 +00:00
Vic
bc36b4e561
implement DoubleEndedIterator for QueryManyIter (#14128)
# Objective

We currently cannot iterate from the back of `QueryManyIter`.

## Solution

Implement `DoubleEndedIterator` for `QueryManyIter` and add a
`fetch_next_back` method. These impls are bounded on the underlying
`entity_iter` implementing `DoubleEndedIterator`.

## Changelog

Added `DoubleEndedIterator` implementation for `QueryManyIter`.
Added the `fetch_next_back` method to `QueryManyIter`.
2024-07-22 18:21:42 +00:00
re0312
e5bf59d712
Recalibrated observe benchmark (#14381)
# Objective

- The event propagation benchmark is largely derived from
bevy_eventlistener. However, it doesn't accurately reflect performance
of bevy side, as our event bubble propagation is based on observer.


## Solution

- added several new benchmarks that focuse on observer itself rather
than event bubble
2024-07-18 18:25:33 +00:00
Lars Frost
dcbd30200e
Make names of closure systems changable (#14369)
# Objective

When using tracing or
[`bevy_mod_debugdump`](https://github.com/jakobhellermann/bevy_mod_debugdump),
the names of function systems produced by closures are either ambiguous
(like `game::mainapp::{closure}` when tracing) or too long
(`bevy_mod_debugdump` includes full type signature if no name given),
which makes debugging with tracing difficult.

## Solution
Add a function `with_name` to rename a system. The proposed API can be
used in the following way:
```rust
app
    .add_systems(Startup, IntoSystem::into_system(|name: SystemName| {
        println!("System name: {}", name.name().to_owned());
    }).with_name("print_test_system"));
```

## Testing
- There is a test in
`bevy_ecs::system:system_name::test_closure_system_name_regular_param`
2024-07-18 18:07:47 +00:00
Martín Maita
72e7a4fed2
Update trigger_observers to operate over slices of data (#14354)
# Objective

- Fixes #14333 

## Solution

- Updated `trigger_observers` signature to operate over a slice instead
of an `Iterator`.
- Updated calls to `trigger_observers` to match the new signature.

---

## Migration Guide

- TBD
2024-07-17 13:01:52 +00:00
Jonathan Chan Kwan Yin
e66cd484a7
Add insert_by_id and try_insert_by_id to EntityCommands (#14283)
# Objective

- Allow queuing insertion of dynamic components to an existing entity

## Solution

- Add `insert_by_id<T: Send + 'static>(commands: &mut EntityCommands,
component_id: ComponentId, value: T)` and the `try_insert_by_id`
counterpart

## Testing

TODO

- Did you test these changes? If so, how?
- Are there any parts that need more testing?
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?

## Alternatives

This PR is not feature-complete for dynamic components. In particular,
it
- only supports one component
- only supports adding components with a known, sized type

These were not implemented because doing so would require enhancing
`CommandQueue` to support pushing unsized commands (or equivalently,
pushing commands with a buffer of data). Even so, the cost would not be
transparent compared to the implementation in this PR, which simply
captures the `ComponentId` and `value: T` into the command closure and
can be easily memcpy'ed to the stack during execution. For example, to
efficiently pass `&[ComponentId]` from the caller to the world, we would
need to:

1. Update `CommandQueue.bytes` from `Vec<MaybeUninit<u8>>` to
`Vec<MaybeUninit<usize>>` so that it has the same alignment as
`ComponentId` (which probably needs to be made `#[repr(transparent)]`
too)
2. After pushing the Command metadata, push padding bytes until the vec
len is a multiple of `size_of::<usize>()`
3. Store `components.len()` in the data
4. memcpy the user-provided `&[ComponentId]` to `CommandQueue.bytes`
5. During execution, round up the data pointer behind the `Command` to
skip padding, then cast the pointer and consume it as a `&[ComponentId]`

The effort here seems unnecessarily high, unless someone else has such a
requirement. At least for the use case I am working with, I only need a
single known type, and if we need multiple components, we could always
enhance this function to accept a `[ComponentId; N]`.

I recommend enhancing the `Bundle` API in the long term to achieve this
goal more elegantly.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Felix Rath <felixm.rath@gmail.com>
2024-07-15 23:29:13 +00:00
SpecificProtagonist
d276525350
Allow non-static trigger targets (#14327)
# Objective

`TriggerTargets` can not be borrowed for use in `World::trigger_targets`

## Solution

Drop `'static` bound on `TriggerEvent`, keep it for `Command` impl.

## Testing

n/a
2024-07-15 16:10:57 +00:00
Ben Frankel
18abe2186c
Fix inaccurate docs for Commands::spawn_empty (#14234)
# Objective

`Commands::spawn_empty` docs say that it queues a command to spawn an
entity, but it doesn't. It immediately reserves an `Entity` to be
spawned at the next flush point, which is possible because
`Entities::reserve_entity()` takes `&self` and no components are added
yet.

## Solution

Fix docs.
2024-07-15 15:32:20 +00:00
Pixelstorm
0f7c548a4a
Component Lifecycle Hook & Observer Trigger for replaced values (#14212)
# Objective

Fixes #14202

## Solution

Add `on_replaced` component hook and `OnReplaced` observer trigger

## Testing

- Did you test these changes? If so, how?
  - Updated & added unit tests

---

## Changelog

- Added new `on_replaced` component hook and `OnReplaced` observer
trigger for performing cleanup on component values when they are
overwritten with `.insert()`
2024-07-15 15:24:15 +00:00
Periwink
da997dd0ea
Allow observer systems to have outputs (#14159)
# Objective

Fixes https://github.com/bevyengine/bevy/issues/14157

## Solution

- Update the ObserverSystem traits to accept an `Out` parameter

## Testing

- Added a test where an observer system has a non-empty output which is
piped into another system

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-07-15 14:59:12 +00:00
Miles Silberling-Cook
ed2b8e0f35
Minimal Bubbling Observers (#13991)
# Objective

Add basic bubbling to observers, modeled off `bevy_eventlistener`.

## Solution

- Introduce a new `Traversal` trait for components which point to other
entities.
- Provide a default `TraverseNone: Traversal` component which cannot be
constructed.
- Implement `Traversal` for `Parent`.
- The `Event` trait now has an associated `Traversal` which defaults to
`TraverseNone`.
- Added a field `bubbling: &mut bool` to `Trigger` which can be used to
instruct the runner to bubble the event to the entity specified by the
event's traversal type.
- Added an associated constant `SHOULD_BUBBLE` to `Event` which
configures the default bubbling state.
- Added logic to wire this all up correctly.

Introducing the new associated information directly on `Event` (instead
of a new `BubblingEvent` trait) lets us dispatch both bubbling and
non-bubbling events through the same api.

## Testing

I have added several unit tests to cover the common bugs I identified
during development. Running the unit tests should be enough to validate
correctness. The changes effect unsafe portions of the code, but should
not change any of the safety assertions.

## Changelog

Observers can now bubble up the entity hierarchy! To create a bubbling
event, change your `Derive(Event)` to something like the following:

```rust
#[derive(Component)]
struct MyEvent;

impl Event for MyEvent {
    type Traverse = Parent; // This event will propagate up from child to parent.
    const AUTO_PROPAGATE: bool = true; // This event will propagate by default.
}
```

You can dispatch a bubbling event using the normal
`world.trigger_targets(MyEvent, entity)`.

Halting an event mid-bubble can be done using
`trigger.propagate(false)`. Events with `AUTO_PROPAGATE = false` will
not propagate by default, but you can enable it using
`trigger.propagate(true)`.

If there are multiple observers attached to a target, they will all be
triggered by bubbling. They all share a bubbling state, which can be
accessed mutably using `trigger.propagation_mut()` (`trigger.propagate`
is just sugar for this).

You can choose to implement `Traversal` for your own types, if you want
to bubble along a different structure than provided by `bevy_hierarchy`.
Implementers must be careful never to produce loops, because this will
cause bevy to hang.

## Migration Guide
+ Manual implementations of `Event` should add associated type `Traverse
= TraverseNone` and associated constant `AUTO_PROPAGATE = false`;
+ `Trigger::new` has new field `propagation: &mut Propagation` which
provides the bubbling state.
+ `ObserverRunner` now takes the same `&mut Propagation` as a final
parameter.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-07-15 13:39:41 +00:00
Giacomo Stevanato
d7080369a7
Fix intra-doc links and make CI test them (#14076)
# Objective

- Bevy currently has lot of invalid intra-doc links, let's fix them!
- Also make CI test them, to avoid future regressions.
- Helps with #1983 (but doesn't fix it, as there could still be explicit
links to docs.rs that are broken)

## Solution

- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
2024-07-11 13:08:31 +00:00
Blake Bedford
2414311079
Fixed #14248 and other URL issues (#14276)
# 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
2024-07-11 12:01:49 +00:00
Bob Gardner
ec1aa48fc6
Created an EventMutator for when you want to mutate an event before reading (#13818)
# Objective

- Often in games you will want to create chains of systems that modify
some event. For example, a chain of damage systems that handle a
DamageEvent and modify the underlying value before the health system
finally consumes the event. Right now this requires either:

* Using a component added to the entity
* Consuming and refiring events

Neither is ideal when really all we want to do is read the events value,
modify it, and write it back.

## Solution

- Create an EventMutator class similar to EventReader but with ResMut<T>
and iterators that return &mut so that events can be mutated.

## Testing

- I replicated all the existing tests for EventReader to make sure
behavior was the same (I believe) and added a number of tests specific
to testing that 1) events can actually be mutated, and that 2)
EventReader sees changes from EventMutator for events it hasn't already
seen.

## Migration Guide

Users currently using `ManualEventReader` should use `EventCursor`
instead. `ManualEventReader` will be removed in Bevy 0.16. Additionally,
`Events::get_reader` has been replaced by `Events::get_cursor`.

Users currently directly accessing the `Events` resource for mutation
should move to `EventMutator` if possible.

---------

Co-authored-by: poopy <gonesbird@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-07-08 14:53:06 +00:00
Mike
33ea3b9f7d
use Display for entity id in log_components (#14164)
# Objective

- Cleanup a doubled `Entity` in log components

```
// Before
2024-07-05T19:54:09.082773Z  INFO bevy_ecs::system::commands: Entity Entity { index: 2, generation: 1 }: ["bevy_transform::components::transform::Transform"]

// After
2024-07-05T19:54:09.082773Z  INFO bevy_ecs::system::commands: Entity 2v1: ["bevy_transform::components::transform::Transform"]
```

---------

Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
2024-07-08 01:03:27 +00:00
Jenya705
330911f1bf
Component Hook functions as attributes for Component derive macro (#14005)
# Objective

Fixes https://github.com/bevyengine/bevy/issues/13972

## Solution

Added 3 new attributes to the `Component` macro.

## Testing

Added `component_hook_order_spawn_despawn_with_macro_hooks`, that makes
the same as `component_hook_order_spawn_despawn` but uses a struct, that
defines it's hooks with the `Component` macro.

---

---------

Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2024-07-08 00:46:00 +00:00
Vic
7e0d262d77
use associated type bounds in QueryManyIter and QueryIter::sort() (#14107)
# Objective

The bounds for query iterators are quite intimidating.

## Solution

With Rust 1.79, [associated type
bounds](https://github.com/rust-lang/rust/pull/122055/) stabilized,
which can simplify the bounds slightly.
2024-07-02 13:39:22 +00:00
Vic
1d907c5668
add missing mention of sort_unstable_by_key in QuerySortedIter docs (#14108)
# Objective

There is a missing mention of `sort_unstable_by_key` in the
`QuerySortedIter` docs.

## Solution

Add it.
2024-07-02 13:27:21 +00:00
Lee-Orr
bd7dcd3f6d
deregister events (#14083)
# Objective

Add ability to de-register events from the EventRegistry (and the
associated World).

The initial reasoning relates to retaining support for Event hot
reloading in `dexterous_developer`.

## Solution

Add a `deregister_events<T: Event>(&mut world)` method to the
`EventRegistry` struct.

## Testing

Added an automated test that verifies the event registry adds and
removes `Events<T>` from the world.

---------

Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-07-01 16:18:14 +00:00
Lura
856b39d821
Apply Clippy lints regarding lazy evaluation and closures (#14015)
# Objective

- Lazily evaluate
[default](https://rust-lang.github.io/rust-clippy/master/index.html#/unwrap_or_default)~~/[or](https://rust-lang.github.io/rust-clippy/master/index.html#/or_fun_call)~~
values where it makes sense
  - ~~`unwrap_or(foo())` -> `unwrap_or_else(|| foo())`~~
  - `unwrap_or(Default::default())` -> `unwrap_or_default()`
  - etc.
- Avoid creating [redundant
closures](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure),
even for [method
calls](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure_for_method_calls)
  - `map(|something| something.into())` -> `map(Into:into)`

## Solution

- Apply Clippy lints:
-
~~[or_fun_call](https://rust-lang.github.io/rust-clippy/master/index.html#/or_fun_call)~~
-
[unwrap_or_default](https://rust-lang.github.io/rust-clippy/master/index.html#/unwrap_or_default)
-
[redundant_closure_for_method_calls](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure_for_method_calls)
([redundant
closures](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure)
is already enabled)

## Testing

- Tested on Windows 11 (`stable-x86_64-pc-windows-gnu`, 1.79.0)
- Bevy compiles without errors or warnings and examples seem to work as
intended
  - `cargo clippy` 
  - `cargo run -p ci -- compile` 

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-07-01 15:54:40 +00:00
Periwink
6573887d5c
Fix error in AnyOf (#14027)
# Objective

- Fixes a correctness error introduced in
https://github.com/bevyengine/bevy/pull/14013 ...

## Solution

I've been playing around a lot of with the access code and I realized
that I introduced a soundness error when trying to simplify the code.
When we have a `Or<(With<A>, With<B>)>` filter, we cannot call
```
  let mut intermediate = FilteredAccess::default();
  $name::update_component_access($name, &mut intermediate);
  _new_access.append_or(&intermediate);
```
because that's just equivalent to adding the new components as `Or`
clauses.
For example if the existing `filter_sets` was `vec![With<C>]`, we would
then get `vec![With<C>, With<A>, With<B>]` which translates to `A or B
or C`.
Instead what we want is `(A and B) or (A and C)`, so we need to have
each new OR clause compose with the existing access like so:
```
let mut intermediate = _access.clone();
// if we previously had a With<C> in the filter_set, this will become `With<C> AND With<A>`
$name::update_component_access($name, &mut intermediate);
_new_access.append_or(&intermediate);
```

## Testing

- Added a unit test that is broken in main, but passes in this PR
2024-06-27 20:20:50 +00:00
Chris Russell
1baa1a11b7
Add missing StaticSystemParam::queue implementation. (#14051)
# Objective

`StaticSystemParam` should delegate all `SystemParam` methods to the
inner param, but it looks like it was missed when the new `queue()`
method was added in #10839.

## Solution

Implement `StaticSystemParam::queue()` to delegate to the inner param.
2024-06-27 15:47:22 +00:00
Vic
e813326c87
add missing sort_unstable_by_key to QueryIter (#14040)
# Objective

`QueryIter::sort_unstable_by_key` is missing.

## Solution

Add `QueryIter::sort_unstable_by_key`.

## Testing

Added the new method to existing test.

## Changelog

Added `QueryIter::sort_unstable_by_key`.
2024-06-27 15:46:19 +00:00
Joseph
2b7d54b300
Emit a warning if the result of EntityCommand::with_entity is not used (#14028)
# Objective

When using combinators such as `EntityCommand::with_entity` to build
commands, it can be easy to forget to apply that command, leading to
dead code. In many cases this doesn't even lead to an unused variable
warning, which can make these mistakes difficult to track down

## Solution

Annotate the method with `#[must_use]`

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-06-26 13:54:55 +00:00
Joseph
a4c621a127
Use an opaque type for EntityCommand::with_entity (#11210)
# Objective

The trait method `with_entity` is used to add an `EntityCommand` to the
command queue. Currently this method returns `WithEntity<C>` which pairs
a command with an `Entity`. By replacing this explicit type with an
opaque type, implementors can override this default implementation by
returning a custom command or closure that does the same thing with a
lower memory footprint.

# Solution

Return an opaque type from the method. As a bonus this file is now
cleaner without the `WithEntity` boilerplate
2024-06-26 12:47:46 +00:00
Periwink
8308ad08a2
AnyOf soundness fix (#14013)
# Objective
Fixes https://github.com/bevyengine/bevy/issues/13993 
PR inspired by https://github.com/bevyengine/bevy/pull/14007 to
accomplish the same thing, but maybe in a clearer fashion.

@Gingeh feel free to take my changes and add them to your PR, I don't
want to steal any credit

---------

Co-authored-by: Gingeh <39150378+Gingeh@users.noreply.github.com>
Co-authored-by: Bob Gardner <rgardner@inworld.ai>
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
2024-06-25 23:54:50 +00:00
Alice Cecile
52e5ad5da7
Don't show .to_bits in Display impl for Entity (#14011)
# Objective

#12469 changed the `Debug` impl for `Entity`, making sure it's actually
accurate for debugging. To ensure that its can still be readily logged
in error messages and inspectors, this PR added a more concise and
human-friendly `Display` impl.

However, users found this form too verbose: the `to_bits` information
was unhelpful and too long. Fixes #13980.

## Solution

- Don't include `Entity::to_bits` in the `Display` implementation for
`Entity`. This information can readily be accessed and logged for users
who need it.
- Also clean up the implementation of `Display` for `DebugName`,
introduced in https://github.com/bevyengine/bevy/pull/13760, to simply
use the new `Display` impl (since this was the desired format there).

## Testing

I've updated an existing test to verify the output of `Entity::display`.

---------

Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
2024-06-25 17:08:24 +00:00
Bob Gardner
4c3b4a445d
Mark events as read during EventReader::par_read (#13836)
# Objective

- Fix issue #13821  

## Solution

- Rewrote the test to ensure that it actually tests the functionality
correctly. Then made the par_read function correctly change the values
of self.reader.last_event_count.

## Testing

- Rewrote the test for par_read to run the system schedule twice,
checking the output each time

---------

Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
2024-06-25 15:36:06 +00:00
Wuketuke
2d30ae437c
improved error message when forgetting to call system apply function … (#13975)
fixes #13944
I literally just added `Did you forget to call SystemState::apply?` to
the error message. I tested it with the code snipped from the Issue and
yeah it works
2024-06-25 12:27:15 +00:00
Carter Anderson
0daa6c510b
Make Observer::with_event (and other variants) unsafe (#13954)
# Objective

`with_event` will result in unsafe casting of event data of the given
type to the type expected by the Observer system. This is inherently
unsafe.

## Solution

Flag `Observer::with_event` and `ObserverDescriptor::with_events` as
unsafe. This will not affect normal workflows as `with_event` is
intended for very specific (largely internal) use cases.

This _should_ be backported to 0.14 before release.

---

## Changelog

- `Observer::with_event` is now unsafe.
- Rename `ObserverDescriptor::with_triggers` to
`ObserverDescriptor::with_events` and make it unsafe.
2024-06-21 18:31:01 +00:00
Rob Parrett
e46e246581
Fix a few "repeated word" typos (#13955)
# Objective

Stumbled on one of these and went digging for more

## Solution

```diff
- word word
+ word
```
2024-06-20 21:35:20 +00:00
Christian Hughes
ee2487a6e2
Change World::inspect_entity to return an Iterator instead of Vec (#13934)
# Objective

Fixes #13933.

## Solution

Changed the return type.

## Testing

Fixed and reused the pre-existing tests for `inspect_entity`.

---

## Migration Guide

- `World::inspect_entity` now returns an `Iterator` instead of a `Vec`.
If you need a `Vec`, immediately collect the iterator:
`world.inspect_entity(entity).collect<Vec<_>>()`
2024-06-19 21:06:35 +00:00
Ben Frankel
e34ecf2f86
Fix typo in ComponentId docs: of -> or (#13932)
# Objective

Fix a typo. Single-character PR :)
2024-06-19 18:51:47 +00:00
Jenya705
6b2d4834e9
IntoSystemConfigs::chain_ignore_deferred's return type fix (#13919)
# Objective

Fixes #13917 

## Solution

Changed `IntoSystemSetConfigs::chain_ignore_deferred`'s return type from
`SystemConfigs` to `SystemSetConfigs`

## Testing

Tried to run the `ecs_guide` example, where `chain` method is replaced
by `chain_ignore_deferred` method

---
2024-06-18 22:21:58 +00:00
dav-wolff
1b0475f234
Fix typo in Query::single_mut docs (#13916)
# Objective

- Fix a typo in documentation for `Query::single_mut`

## Solution

- Change `item` to `items`

## Testing

- I built the documentation and it looked fine.
- Since this only affects a doc comment, no further testing should be
necessary.

---

## Changelog

> This section is optional. If this was a trivial fix, or has no
externally-visible impact, you can delete this section.

- Fixed a typo in the documentation for Query.
2024-06-18 19:55:37 +00:00
Jan Hohenheim
6273227e09
Fix lints introduced in Rust beta 1.80 (#13899)
Resolves #13895

Mostly just involves being more explicit about which parts of the docs
belong to a list and which begin a new paragraph.
- found a few docs that were malformed because of exactly this, so I
fixed that by introducing a paragraph
- added indentation to nearly all multiline lists
- fixed a few minor typos
- added `#[allow(dead_code)]` to types that are needed to test
annotations but are never constructed
([here](https://github.com/bevyengine/bevy/pull/13899/files#diff-b02b63604e569c8577c491e7a2030d456886d8f6716eeccd46b11df8aac75dafR1514)
and
[here](https://github.com/bevyengine/bevy/pull/13899/files#diff-b02b63604e569c8577c491e7a2030d456886d8f6716eeccd46b11df8aac75dafR1523))
- verified that  `cargo +beta run -p ci -- lints` passes
- verified that `cargo +beta run -p ci -- test` passes
2024-06-17 17:22:01 +00:00
James O'Brien
335dcf96a2
Update observer archetype flags for sparse components (#13886)
# Objective

- Fixes #13885 

## Solution

- Update the flags correctly on archetype creation

## Testing

- Added `observer_order_insert_remove_sparse` to catch regressions.
2024-06-17 15:15:30 +00:00
Brezak
16e02e1889
Use a unstable sort to sort component ids in bevy_ecs (#13789)
# Objective

While writing code for the `bevy_ecs` I noticed we were using a
unnecessarily stable sort to sort component ids

## Solution

- Sort component ids with a unstable sort
- Comb the bevy_ecs crate for any other obvious inefficiencies.
- Don't clone component vectors when inserting an archetype.

## Testing

I ran `cargo test -p bevy_ecs`. Everything else I leave to CI.

## Profiling

I measured about a 1% speed increase when spawning entities directly
into a world. Since the difference is so small (and might just be noise)
I didn't bother to figure out which of change if any made the biggest
difference.
<details>
<summary> Tracy data </summary>
Yellow is this PR. Red is the commit I branched from.


![image](https://github.com/bevyengine/bevy/assets/59848927/f1a5c95d-a882-4dfb-ac07-dd2922273b91)

</details>

<details>
<summary>Methodology</summary>
I created a system that spawn a 1000 entities each with the same 30
components each frame, and then I measured it's run time. The unusually
high number of components was chosen because the standard library [will
use a insertion sort for slices under 20
elements](0de24a5177/library/core/src/slice/sort.rs (L1048-L1049)).
This holds for both stable and unstable sorts.
</details>
2024-06-17 14:56:19 +00:00
James O'Brien
eb3c81374a
Generalised ECS reactivity with Observers (#10839)
# Objective

- Provide an expressive way to register dynamic behavior in response to
ECS changes that is consistent with existing bevy types and traits as to
provide a smooth user experience.
- Provide a mechanism for immediate changes in response to events during
command application in order to facilitate improved query caching on the
path to relations.

## Solution

- A new fundamental ECS construct, the `Observer`; inspired by flec's
observers but adapted to better fit bevy's access patterns and rust's
type system.

---

## Examples
There are 3 main ways to register observers. The first is a "component
observer" that looks like this:
```rust
world.observe(|trigger: Trigger<OnAdd, Transform>, query: Query<&Transform>| {
    let transform = query.get(trigger.entity()).unwrap();
});
```
The above code will spawn a new entity representing the observer that
will run it's callback whenever the `Transform` component is added to an
entity. This is a system-like function that supports dependency
injection for all the standard bevy types: `Query`, `Res`, `Commands`
etc. It also has a `Trigger` parameter that provides information about
the trigger such as the target entity, and the event being triggered.
Importantly these systems run during command application which is key
for their future use to keep ECS internals up to date. There are similar
events for `OnInsert` and `OnRemove`, and this will be expanded with
things such as `ArchetypeCreated`, `TableEmpty` etc. in follow up PRs.

Another way to register an observer is an "entity observer" that looks
like this:
```rust
world.entity_mut(entity).observe(|trigger: Trigger<Resize>| {
    // ...
});
```
Entity observers run whenever an event of their type is triggered
targeting that specific entity. This type of observer will de-spawn
itself if the entity (or entities) it is observing is ever de-spawned so
as to not leave dangling observers.

Entity observers can also be spawned from deferred contexts such as
other observers, systems, or hooks using commands:
```rust
commands.entity(entity).observe(|trigger: Trigger<Resize>| {
    // ...
});
```

Observers are not limited to in built event types, they can be used with
any type that implements `Event` (which has been extended to implement
Component). This means events can also carry data:

```rust
#[derive(Event)]
struct Resize { x: u32, y: u32 }

commands.entity(entity).observe(|trigger: Trigger<Resize>, query: Query<&mut Size>| {
    let event = trigger.event();
    // ...
});

// Will trigger the observer when commands are applied.
commands.trigger_targets(Resize { x: 10, y: 10 }, entity);
```

You can also trigger events that target more than one entity at a time:

```rust
commands.trigger_targets(Resize { x: 10, y: 10 }, [e1, e2]);
```

Additionally, Observers don't _need_ entity targets:

```rust
app.observe(|trigger: Trigger<Quit>| {
})

commands.trigger(Quit);
```

In these cases, `trigger.entity()` will be a placeholder.

Observers are actually just normal entities with an `ObserverState` and
`Observer` component! The `observe()` functions above are just shorthand
for:

```rust
world.spawn(Observer::new(|trigger: Trigger<Resize>| {});
```

This will spawn the `Observer` system and use an `on_add` hook to add
the `ObserverState` component.

Dynamic components and trigger types are also fully supported allowing
for runtime defined trigger types.

## Possible Follow-ups
1. Deprecate `RemovedComponents`, observers should fulfill all use cases
while being more flexible and performant.
2. Queries as entities: Swap queries to entities and begin using
observers listening to archetype creation triggers to keep their caches
in sync, this allows unification of `ObserverState` and `QueryState` as
well as unlocking several API improvements for `Query` and the
management of `QueryState`.
3. Trigger bubbling: For some UI use cases in particular users are
likely to want some form of bubbling for entity observers, this is
trivial to implement naively but ideally this includes an acceleration
structure to cache hierarchy traversals.
4. All kinds of other in-built trigger types.
5. Optimization; in order to not bloat the complexity of the PR I have
kept the implementation straightforward, there are several areas where
performance can be improved. The focus for this PR is to get the
behavior implemented and not incur a performance cost for users who
don't use observers.

I am leaving each of these to follow up PR's in order to keep each of
them reviewable as this already includes significant changes.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-06-15 01:33:26 +00:00
Alice Cecile
2cffd14923
Ensure that events are updated even when using a bare-bones Bevy App (#13808)
# Objective

As discovered in
https://github.com/Leafwing-Studios/leafwing-input-manager/issues/538,
there appears to be some real weirdness going on in how event updates
are processed between Bevy 0.13 and Bevy 0.14.

To identify the cause and prevent regression, I've added tests to
validate the intended behavior.
My initial suspicion was that this would be fixed by
https://github.com/bevyengine/bevy/pull/13762, but that doesn't seem to
be the case.

Instead, events appear to never be updated at all when using `bevy_app`
by itself. This is part of the problem resolved by
https://github.com/bevyengine/bevy/pull/11528, and introduced by
https://github.com/bevyengine/bevy/pull/10077.

After some investigation, it appears that `signal_event_update_system`
is never added using a bare-bones `App`, and so event updates are always
skipped.

This can be worked around by adding your own copy to a
later-in-the-frame schedule, but that's not a very good fix.

## Solution

Ensure that if we're not using a `FixedUpdate` schedule, events are
always updated every frame.

To do this, I've modified the logic of `event_update_condition` and
`event_update_system` to clearly and correctly differentiate between the
two cases: where we're waiting for a "you should update now" signal and
where we simply don't care.

To encode this, I've added the `ShouldUpdateEvents` enum, replacing a
simple `bool` in `EventRegistry`'s `needs_update` field.

Now, both tests pass as expected, without having to manually add a
system!

## Testing

I've written two parallel unit tests to cover the intended behavior:

1. Test that `iter_current_update_events` works as expected in
`bevy_ecs`.
2. Test that `iter_current_update_events` works as expected in
`bevy_app`

I've also added a test to verify that event updating works correctly in
the presence of a fixed main schedule, and a second test to verify that
fixed updating works at all to help future authors narrow down failures.

## Outstanding

- [x] figure out why the `bevy_app` version of this test fails but the
`bevy_ecs` version does not
- [x] figure out why `EventRegistry::run_updates` isn't working properly
- [x] figure out why `EventRegistry::run_updates` is never getting
called
- [x] figure out why `event_update_condition` is always returning false
- [x] figure out why `EventRegistry::needs_update` is always false
- [x] verify that the problem is a missing `signal_events_update_system`

---------

Co-authored-by: Mike <mike.hsu@gmail.com>
2024-06-12 14:28:51 +00:00
CatThingy
f23c686fcf
Fix minor typos in query join docs (#13812)
# Objective

- Correct typos in docs for `Query::join`'s docs

## Solution

- Fix them

Co-authored-by: François Mockers <mockersf@gmail.com>
2024-06-11 23:24:53 +00:00
Mike
07a85676b3
Revert "constrain WorldQuery::init_state argument to ComponentInitial… (#13804)
…izer (#13442)"

This reverts commit 5cfb063d4a.

- This PR broke bevy-trait-query, which needs to be able to write a
resource in init_state. See #13798 for more details.
- Note this doesn't fix everything as transmutes for bevy-trait-query
will still be broken,. But the current usage in that crate is UB, so we
need to find another solution.
2024-06-11 22:54:42 +00:00
Bob Gardner
2ccdae7489
Split event.rs into a full module. (#13801)
# Objective

- Split the bevy_ecs::events module so it's easier to work with

## Solution

- Split the event.rs file across multiple files, made sure all tests
passed, and exports from the module were the same as previous

## Testing

- All automated tests pass.
2024-06-10 21:45:01 +00:00
Chris Juchem
49661b99fe
Remove extra call to clear_trackers (#13762)
Fixes #13758.

# Objective

Calling `update` on the main app already calls `clear_trackers`. Calling
it again in `SubApps::update` caused RemovedCompenet Events to be
cleared earlier than they should be.

## Solution

- Don't call clear_trackers an extra time.

## Testing

I manually tested the fix with this unit test: 
```
#[cfg(test)]
mod test {
    use crate::core::{FrameCount, FrameCountPlugin};
    use crate::prelude::*;

    #[test]
    fn test_next_frame_removal() {
        #[derive(Component)]
        struct Foo;

        #[derive(Resource)]
        struct RemovedCount(usize);

        let mut app = App::new();
        app.add_plugins(FrameCountPlugin);
        app.add_systems(Startup, |mut commands: Commands| {
            for _ in 0..100 {
                commands.spawn(Foo);
            }
            commands.insert_resource(RemovedCount(0));
        });

        app.add_systems(First, |counter: Res<FrameCount>| {
            println!("Frame {}:", counter.0)
        });

        fn detector_system(
            mut removals: RemovedComponents<Foo>,
            foos: Query<Entity, With<Foo>>,
            mut removed_c: ResMut<RemovedCount>,
        ) {
            for e in removals.read() {
                println!("  Detected removed Foo component for {e:?}");
                removed_c.0 += 1;
            }
            let c = foos.iter().count();
            println!("  Total Foos: {}", c);
            assert_eq!(c + removed_c.0, 100);
        }
        fn deleter_system(foos: Query<Entity, With<Foo>>, mut commands: Commands) {
            foos.iter().next().map(|e| {
                commands.entity(e).remove::<Foo>();
            });
        }
        app.add_systems(Update, (detector_system, deleter_system).chain());

        app.update();
        app.update();
        app.update();
        app.update();
    }
}
```
2024-06-10 18:06:05 +00:00
Periwink
93f3432400
Update serialize flag for bevy_ecs (#13740)
# Objective

There were some issues with the `serialize` feature:
- `bevy_app` had a `serialize` feature and a dependency on `serde` even
there is no usage of serde at all inside `bevy_app`
- the `bevy_app/serialize` feature enabled `bevy_ecs/serde`, which is
strange
- `bevy_internal/serialize` did not enable `bevy_app/serialize` so there
was no way of serializing an Entity in bevy 0.14

## Solution

- Remove `serde` and `bevy_app/serialize` 
- Add a `serialize` flag on `bevy_ecs` that enables `serde`
- ` bevy_internal/serialize` now enables `bevy_ecs/serialize`
2024-06-10 16:37:59 +00:00
T.J. Given
70a38ab1f6
Re-name and Extend Run Conditions API (#13784)
# Objective

- My attempt at fulfilling #13629.

## Solution

Renames the `and_then` / `or_else` run condition methods to `and` /
`or`, respectively.

Extends the run conditions API to include a suite of binary logical
operators:
- `and`
- `or`
- `nand`
- `nor`
- `xor`
- `xnor`

## Testing

- Did you test these changes? If so, how?
- The test **run_condition_combinators** was extended to include the
added run condition combinators. A **double_counter** system was added
to test for combinators running on even count cycles.

- Are there any parts that need more testing?
- I'm not too sure how I feel about the "counter" style of testing but I
wanted to keep it consistent. If it's just a unit test I would prefer
simply to just assert `true` == _combinator output_ or `false` ==
_combinator output_ .

- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Nothing too specific. The added methods should be equivalent to the
logical operators they are analogous to (`&&` , `||`, `^`, `!`).

- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
    - Should not be relevant, I'm using Windows.

## Changelog

- What changed as a result of this PR?
    - The run conditions API.

- If applicable, organize changes under "Added", "Changed", or "Fixed"
sub-headings
    - Changed:
        - `and_then` run condition combinator renamed to simply `and`
        - `or_else` run condition combinator renamed to simply `or`
    - Added:
        - `nand` run condition combinator.
        - `nor` run condition combinator.
        - `xor` run condition combinator.
        - `xnor` run condition combinator.

## Migration Guide

- The `and_then` run condition method has been replaced with the `and`
run condition method.
- The `or_else` run condition method has been replaced with the `or` run
condition method.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Andres O. Vela <andresovela@users.noreply.github.com>
2024-06-10 13:41:56 +00:00
thebluefish
7c9c6ff27f
Fix EntityCommands::despawn docs (#13774)
# Objective

The `EntityCommands::despawn` method was previously changed from
panicking behavior to a warning, but the docs continue to state that it
panics.

## Solution

- Removed panic section, copied warning blurb from `World::despawn`
- Adds a similar warning blurb to
`DespawnRecursiveExt::despawn_recursive` and
`DespawnRecursiveExt::despawn_descendants`
2024-06-09 17:59:19 +00:00
Zachary Harrold
3bfc427666
Add mappings to EntityMapper (#13727)
# Objective

- Fixes #13703

## Solution

- Added `mappings` to the `EntityMapper` trait, which returns an
iterator over currently tracked `Entity` to `Entity` mappings.
- Added `DynEntityMapper` as an [object
safe](https://doc.rust-lang.org/reference/items/traits.html#object-safety)
alternative to `EntityMapper`.
- Added `assert_object_safe` as a helper for ensuring traits are object
safe.

## Testing

- Added new unit test `entity_mapper_iteration` which tests the
`SceneEntityMapper` implementation of `EntityMapper::mappings`.
- Added unit tests to ensure `DynEntityMapper`, `DynEq` and `DynHash`
are object safe.
- Passed CI on my Windows 10 development environment

---

## Changelog

- Added `mappings` to `EntityMapper` trait.

## Migration Guide

- If you are implementing `EntityMapper` yourself, you can use the below
as a stub implementation:

```rust
fn mappings(&self) -> impl Iterator<Item = (Entity, Entity)> {
    unimplemented!()
}
```

- If you were using `EntityMapper` as a trait object (`dyn
EntityMapper`), instead use `dyn DynEntityMapper` and its associated
methods.

## Notes

- The original issue proposed returning a `Vec` from `EntityMapper`
instead of an `impl Iterator` to preserve its object safety. This is a
simpler option, but also forces an allocation where it isn't strictly
needed. I've opted for this split into `DynEntityMapper` and
`EntityMapper` as it's been done several times across Bevy already, and
provides maximum flexibility to users.
- `assert_object_safe` is an empty function, since the assertion
actually happens once you try to use a `dyn T` for some trait `T`. I
have still added this function to clearly document what object safety is
within Bevy, and to create a standard way to communicate that a given
trait must be object safe.
- Other traits should have tests added to ensure object safety, but I've
left those off to avoid cluttering this PR further.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-06-08 12:52:23 +00:00
Mason Boeman
2b6bfdb5ea
Add dynamic slice based variants of get_many_entities methods (#13584)
# Objective

Add slice based variants of existing `get_many_entities` functions on
`World`. This allows for a collection of entries to be looked up mutably
or immutably instead of requiring a compile time constant number.

## Solution

We just take slices and return Vectors.

the following functions have been added:
- `get_many_entities_dynamic`
- `get_many_entities_dynamic_mut`
- `get_many_entities_from_set_mut`

## Testing

- Doc tests, which pass when run through Miri
2024-06-04 15:29:51 +00:00
Rob Parrett
ab2add64fa
Fix a few typos (#13404)
# Objective

Fix a few typos I spotted while looking over #13347

## Solution

Fix em
2024-06-04 00:51:03 +00:00
Alice Cecile
ec7b3490f6
Add on_unimplemented Diagnostics to Most Public Traits (#13347) (#13662)
# Objective

- #13414 did not have the intended effect.
- #13404 is still blocked

## Solution

- Re-adds #13347.

Co-authored-by: Zachary Harrold <zac@harrold.com.au>
Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-06-04 00:31:34 +00:00
Brandon Reinhart
7570c9f3d2
Map entities from a resource when written to the world. (#13650)
# 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
2024-06-03 16:33:24 +00:00
Gonçalo Rica Pais da Silva
36f2542f63
feat: Reflection implementations on Identifier (#13648)
# Objective

- Follow-up on some changes in #11498
- Unblock using `Identifier` to replace `ComponentId` internals.

## Solution

- Implement the same `Reflect` impls from `Entity` onto `Identifier` as
they share same/similar purposes,

## Testing

- No compile errors. Currently `Identifier` has no serialization impls,
so there's no need to test a serialization/deserialization roundtrip to
ensure correctness.

---

## Changelog

### Added

- Reflection implementations on `Identifier`.
2024-06-03 16:33:14 +00:00
Dmytro Banin
7307d76fb3
Make SceneEntityMapper constructor/destructor public (#13630)
# Objective

`SceneEntityMapper` seems like it could be generally useful.

## Solution

Allow end users to call `SceneEntityMapper::new` and
`SceneEntityMapper::finish`.
2024-06-03 13:37:53 +00:00
Periwink
223a54629c
Add Hash for Tick (#13525)
# Objective

- There are some situations (networking) where storing `Tick` as a key
in a hashmap is useful
2024-06-03 13:19:00 +00:00
Dmytro Banin
42d80375db
Add ability to clear all components on an entity via EntityWorldMut (#13588)
# Objective

Adds capability to clear all components on an entity without de-spawning
said entity.

## Testing

The function calls `remove_by_id` on every component in the entity
archetype - wasn't sure if it's worth going out of our way to create a
test for this considering `remove_by_id` is already unit tested.

---

## Changelog

Added `clear` function to `EntityWorldMut` which removes all components
on an entity.

## Migration Guide

N/A

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-05-31 16:42:03 +00:00
Vic
5cfb063d4a
constrain WorldQuery::init_state argument to ComponentInitializer (#13442)
# Objective

In #13343, `WorldQuery::get_state` was constrained from `&World` as the
argument to `&Components`, but `WorldQuery::init_state` hasn't yet been
changed from `&mut World` to match.

Fixes #13358

## Solution

Create a wrapper around `&mut Components` and `&mut Storages` that can
be obtained from `&mut World` with a `component_initializer` method.
This new `ComponentInitializer` re-exposes the API on `&mut Components`
minus the `&mut Storages` parameter where it was present. For the
`&Components` API, it simply derefs to its `components` field.

## Changelog

### Added
The `World::component_initializer` method.
The `ComponentInitializer` struct that re-exposes `Components` API.
### Changed
`WorldQuery::init_state` now takes `&mut ComponentInitializer` instead
of `&mut World`.

## Migration Guide
Instead of passing `&mut World` to `WorldQuery::init_state` directly,
pass in a mutable reference to the struct returned from
`World::component_initializer`.
2024-05-30 14:47:22 +00:00