Commit Graph

1818 Commits

Author SHA1 Message Date
Nathan Fenner
755adae0f8
fix test for .iter().sort() to include data to sort (#18127)
The test case `query_iter_sorts` was doing lots of comparisons to ensure
that various query arrays were sorted, but the arrays were all empty.

This PR spawns some entities so that the entity lists to compare not
empty, and sorting can actually be tested for correctness.
2025-03-03 06:24:43 +00:00
Alice Cecile
2ad5908e58
Make Query::single (and friends) return a Result (#18082)
# Objective

As discussed in #14275, Bevy is currently too prone to panic, and makes
the easy / beginner-friendly way to do a large number of operations just
to panic on failure.

This is seriously frustrating in library code, but also slows down
development, as many of the `Query::single` panics can actually safely
be an early return (these panics are often due to a small ordering issue
or a change in game state.

More critically, in most "finished" products, panics are unacceptable:
any unexpected failures should be handled elsewhere. That's where the
new

With the advent of good system error handling, we can now remove this.

Note: I was instrumental in a) introducing this idea in the first place
and b) pushing to make the panicking variant the default. The
introduction of both `let else` statements in Rust and the fancy system
error handling work in 0.16 have changed my mind on the right balance
here.

## Solution

1. Make `Query::single` and `Query::single_mut` (and other random
related methods) return a `Result`.
2. Handle all of Bevy's internal usage of these APIs.
3. Deprecate `Query::get_single` and friends, since we've moved their
functionality to the nice names.
4. Add detailed advice on how to best handle these errors.

Generally I like the diff here, although `get_single().unwrap()` in
tests is a bit of a downgrade.

## Testing

I've done a global search for `.single` to track down any missed
deprecated usages.

As to whether or not all the migrations were successful, that's what CI
is for :)

## Future work

~~Rename `Query::get_single` and friends to `Query::single`!~~

~~I've opted not to do this in this PR, and smear it across two releases
in order to ease the migration. Successive deprecations are much easier
to manage than the semantics and types shifting under your feet.~~

Cart has convinced me to change my mind on this; see
https://github.com/bevyengine/bevy/pull/18082#discussion_r1974536085.

## Migration guide

`Query::single`, `Query::single_mut` and their `QueryState` equivalents
now return a `Result`. Generally, you'll want to:

1. Use Bevy 0.16's system error handling to return a `Result` using the
`?` operator.
2. Use a `let else Ok(data)` block to early return if it's an expected
failure.
3. Use `unwrap()` or `Ok` destructuring inside of tests.

The old `Query::get_single` (etc) methods which did this have been
deprecated.
2025-03-02 19:51:56 +00:00
RobWalt
73ffd9a508
chore: update compile fail test stderr files (#18056)
I noticed this while working on #18017 . Some of the `stderr`
compile_fail tests were updated while I generated the output for the new
tests I introduced in the mentioned PR.

I'm on rust 1.85.0
2025-03-01 00:31:55 +00:00
JaySpruce
ad1691e44a
Update EntityCommands::trigger to check for the entity's existence (#18071)
## Objective

`EntityCommands::trigger` internally uses `Commands::trigger_targets`,
which means it gets queued using `Commands::queue` rather
`EntityCommands::queue`. This previously wouldn't have made much
difference, but now entity commands check whether the entity exists, and
that check never happens in this case.

## Solution

- Add `entity_command::trigger`, which calls the same function as before
(`World::trigger_targets_with_caller`) but through the `EntityWorldMut`
passed to entity commands.
- Change `EntityCommands::trigger` to queue the new entity command
normally.
2025-03-01 00:08:03 +00:00
Greeble
780f658f2c
Update ChildOf deprecation advice to match new layout (#18089)
https://github.com/bevyengine/bevy/pull/17905 replaced `ChildOf(entity)`
with `ChildOf { parent: entity }`, but some deprecation advice was
overlooked. Also corrected formatting in documentation.

## Testing

Added a `set_parent` to a random example. Confirmed that the deprecation
warning shows and the advice can be pasted in.
2025-02-28 23:15:23 +00:00
Carter Anderson
b73811d40e
Remove ChildOf::get and Deref impl (#18080)
# Objective

There are currently three ways to access the parent stored on a ChildOf
relationship:

1. `child_of.parent` (field accessor)
2. `child_of.get()` (get function)
3. `**child_of` (Deref impl)

I will assert that we should only have one (the field accessor), and
that the existence of the other implementations causes confusion and
legibility issues. The deref approach is heinous, and `child_of.get()`
is significantly less clear than `child_of.parent`.

## Solution

Remove `impl Deref for ChildOf` and `ChildOf::get`.

The one "downside" I'm seeing is that:

```rust
entity.get::<ChildOf>().map(ChildOf::get)
```
Becomes this:

```rust
entity.get::<ChildOf>().map(|c| c.parent)
```

I strongly believe that this is worth the increased clarity and
consistency. I'm also not really a huge fan of the "pass function
pointer to map" syntax. I think most people don't think this way about
maps. They think in terms of a function that takes the item in the
Option and returns the result of some action on it.

## Migration Guide

```rust
// Before
**child_of
// After
child_of.parent

// Before
child_of.get()
// After
child_of.parent

// Before
entity.get::<ChildOf>().map(ChildOf::get)
// After
entity.get::<ChildOf>().map(|c| c.parent)
```
2025-02-27 23:11:03 +00:00
JaySpruce
058497e0bb
Change Commands::get_entity to return Result and remove panic from Commands::entity (#18043)
## Objective

Alternative to #18001.

- Now that systems can handle the `?` operator, `get_entity` returning
`Result` would be more useful than `Option`.
- With `get_entity` being more flexible, combined with entity commands
now checking the entity's existence automatically, the panic in `entity`
isn't really necessary.

## Solution

- Changed `Commands::get_entity` to return `Result<EntityCommands,
EntityDoesNotExistError>`.
- Removed panic from `Commands::entity`.
2025-02-27 21:05:16 +00:00
Tim Overbeek
ccb7069e7f
Change ChildOf to Childof { parent: Entity} and support deriving Relationship and RelationshipTarget with named structs (#17905)
# Objective

fixes #17896 

## Solution

Change ChildOf ( Entity ) to ChildOf { parent: Entity }

by doing this we also allow users to use named structs for relationship
derives, When you have more than 1 field in a struct with named fields
the macro will look for a field with the attribute #[relationship] and
all of the other fields should implement the Default trait. Unnamed
fields are still supported.

When u have a unnamed struct with more than one field the macro will
fail.
Do we want to support something like this ? 

```rust
 #[derive(Component)]
 #[relationship_target(relationship = ChildOf)]
 pub struct Children (#[relationship] Entity, u8);
```
I could add this, it but doesn't seem nice.
## Testing

crates/bevy_ecs - cargo test


## Showcase


```rust

use bevy_ecs::component::Component;
use bevy_ecs::entity::Entity;

 #[derive(Component)]
 #[relationship(relationship_target = Children)]
 pub struct ChildOf {
     #[relationship]
     pub parent: Entity,
     internal: u8,
 };

 #[derive(Component)]
 #[relationship_target(relationship = ChildOf)]
 pub struct Children {
     children: Vec<Entity>
 };

```

---------

Co-authored-by: Tim Overbeek <oorbecktim@Tims-MacBook-Pro.local>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-042.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-059.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-054.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-027.client.nl.eduvpn.org>
2025-02-27 19:22:17 +00:00
JaySpruce
67146bdef7
Add missing unsafe to entity_command::insert_by_id and make it more configurable (#18052)
## Objective

`insert_by_id` is unsafe, but I forgot to add that to the
manually-queueable version in `entity_command`.

It also can only insert using `InsertMode::Replace`, when it could
easily be configurable by threading an `InsertMode` parameter to the
final `BundleInserter::insert` call.

## Solution

- Add `unsafe` and safety comment.
- Add `InsertMode` parameter to `entity_command::insert_by_id`,
`EntityWorldMut::insert_by_id_with_caller`, and
`EntityWorldMut::insert_dynamic_bundle`.
- Add `InsertMode` parameter to `entity_command::insert` and remove
`entity_command::insert_if_new`, for consistency with the other
manually-queued insertion commands.
2025-02-27 06:20:32 +00:00
urben1680
2f384643c3
Bubble sync points if ignore_deferred, do not ignore if target system is exclusive (#17880)
# Objective

Fixes #17828

This fixes two bugs:

1. Exclusive systems should see the effect of all commands queued to
that point. That does not happen when the system is configured with
`*_ignore_deferred` which may lead to surprising situations. These
configurations should not behave like that.
2. If `*_ignore_deferred` is used, no sync point may be added at all
**after** the config. Currently this can happen if the last nodes in
that config have no deferred parameters themselves. Instead, sync points
should always be added after such a config, so long systems have
deferred parameters.

## Solution

1. When adding sync points on edges, do not consider
`AutoInsertApplyDeferredPass::no_sync_edges` if the target is an
exclusive system.
2. when going through the nodes in a directed way, store the information
that `AutoInsertApplyDeferredPass::no_sync_edges` suppressed adding a
sync point at the target node. Then, when the target node is evaluated
later by the iteration and that prior suppression was the case, the
target node will behave like it has deferred parameters even if the
system itself does not.

## Testing

I added a test for each bug, please let me know if more are wanted and
if yes, which cases you would want to see.
These tests also can be read as examples how the current code would
fail.
2025-02-26 20:39:23 +00:00
Chris Russell
94e6fa168f
Fix unsoundness in QueryIter::sort_by (#17826)
# Objective

`QueryIter::sort_by()` is unsound. It passes the lens items with the
full `'w` lifetime, and a malicious user could smuggle them out of the
closure where they could alias with the query results.

## Solution

Make the sort closures generic in the lifetime parameter of the lens
item. This ensures the lens items cannot outlive the call to the
closure.

## Testing

Added a compile-fail test that demonstrates the unsound pattern.

## Migration Guide

The `sort` family of methods on `QueryIter` unsoundly gave access
`L::Item<'w>` with the full `'w` lifetime. It has been shortened to
`L::Item<'w>` so that items cannot escape the comparer. If you get
lifetime errors using these methods, you will need to make the comparer
generic in the new lifetime. Often this can be done by replacing named
`'w` with `'_`, or by replacing the use of a function item with a
closure.

```rust
// Before: Now fails with "error: implementation of `FnMut` is not general enough"
query.iter().sort_by::<&C>(Ord::cmp);
// After: Wrap in a closure
query.iter().sort_by::<&C>(|l, r| Ord::cmp(l, r));

query.iter().sort_by::<&C>(comparer);
// Before: Uses specific `'w` lifetime from some outer scope
// now fails with "error: implementation of `FnMut` is not general enough"
fn comparer(left: &&'w C, right: &&'w C) -> Ordering { /* ... */ }
// After: Accepts any lifetime using inferred lifetime parameter
fn comparer(left: &&C, right: &&C) -> Ordering { /* ... */ }
2025-02-26 20:36:37 +00:00
Sou1gh0st
f2b37c733e
Deduplicate register_inherited_required_components (#16519)
# Objective
- Fixes #16416 

## Solution
- Add a intermediate temporary mutable `RequiredComponents` to get avoid
of the borrowing issues.

## Testing

- I have run `cargo test --package bevy_ecs -- --exact --show-output`
and past all the tests.
2025-02-25 23:59:58 +00:00
SpecificProtagonist
25cee420e4
do_not_recommend interned Labels (#17950)
# Objective

Follow up on #17441 now that `do_not_recommend` is stable.

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-02-25 23:46:21 +00:00
JaySpruce
36a2f7fdf1
Remove unnecessary bounds on EntityClonerBuilder::without_required_components (#17969)
## Objective

The closure argument for
`EntityClonerBuilder::without_required_components` has `Send + Sync +
'static` bounds, but the closure immediately gets called and never needs
to be sent anywhere. (This was my fault :P )

## Solution

Remove the bounds so that users aren't unnecessarily restricted.

I also took the opportunity to expand the tests a little.
2025-02-25 23:34:46 +00:00
Tristan Maindron
0f153ffb44
Prevent last_trigger_id from overflowing (#17978)
# Objective

This prevents overflowing the `last_trigger_id` property that leads to a
panic in debug mode.

```bash
panicked at C:\XXX\.cargo\registry\src\index.crates.io-6f17d22bba15001f\bevy_ecs-0.15.2\src\world\unsafe_world_cell.rs:630:18:
attempt to add with overflow
Encountered a panic when applying buffers for system `bevy_sprite::calculate_bounds_2d`!
Encountered a panic in system `bevy_ecs::schedule::executor::apply_deferred`!
```

## Solution

As this value is only used for detecting a change, we can wrap when it
reaches max value.

## Testing

This can be verified by running `cargo run --example observers`
2025-02-25 23:12:51 +00:00
Brezak
b43c8f8c4f
Add methods to add single entity relationships (#18038)
# Objective

Closes #17572

## Solution

Add the `add_one_related` methods to `EntityCommands` and
`EntityWorldMut`.

## Testing

Clippy

---

## Showcase

The `EntityWorldMut` and `FilteredResourcesMut` now include the
`add_one_related` method if you just want to relate 2 entities.
2025-02-25 23:07:44 +00:00
Zachary Harrold
20813aed64
Handle TriggerTargets that are combinations for components/entities (#18024)
# Objective

* Fixes https://github.com/bevyengine/bevy/issues/14074
* Applies CI fixes for #16326

It is currently not possible to issues a trigger that targets a specific
list of components AND a specific list of entities

## Solution

We can now use `((A, B), (entity_1, entity_2))` as a trigger target, as
well as the reverse

## Testing

Added a unit test.

The triggering rules for observers are quite confusing:

Triggers once per entity target

For each entity target, an observer system triggers if any of its
components matches the trigger target components (but it triggers at
most once, since we use an internal counter to make sure that an
observer can run at most once per entity target)

(copied from #14563)
(copied from #16326)

## Notes

All credit to @BenjaminBrienen and @cBournhonesque! Just applying a
small fix to this PR so it can be merged.

---------

Co-authored-by: Benjamin Brienen <Benjamin.Brienen@outlook.com>
Co-authored-by: Christian Hughes <xdotdash@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-02-24 23:57:34 +00:00
VitalyR
6bae04ab36
Add usage notes for register_component (#18011)
# Objective

- Add usage notes for `register_component`, fixes #16447


## Testing

CI
2025-02-24 21:47:25 +00:00
Vic
a1717331e4
implement UniqueEntityArray (#17954)
# Objective

Continuation of #17589 and #16547.

`get_many` is last of the `many` methods with a missing `unique`
counterpart.
It both takes and returns arrays, thus necessitates a matching
`UniqueEntityArray` type!
Plus, some slice methods involve returning arrays, which are currently
missing from `UniqueEntitySlice`.

## Solution

Add the type, the related methods and trait impls.

Note that for this PR, we abstain from some methods/trait impls that
create `&mut UniqueEntityArray`, because it can be successfully
mem-swapped. This can potentially invalidate a larger slice, which is
the same reason we punted on some mutable slice methods in #17589. We
can follow-up on all of these together in a following PR.

The new `unique_array` module is not glob-exported, because the trait
alias `unique_array::IntoIter` would conflict with
`unique_vec::IntoIter`.
The solution for this is to make the various `unique_*` modules public,
which I intend to do in yet another PR.
2025-02-24 21:36:59 +00:00
andriyDev
bb09751cf0
Fix observer/hook OnReplace and OnRemove triggering when removing a bundle even when the component is not present on the entity (#17942)
# Objective

- Fixes #17897.

## Solution

- When removing components, we filter the list of components in the
removed bundle based on whether they are actually in the archetype.

## Testing

- Added a test.
2025-02-24 21:25:31 +00:00
Zachary Harrold
76e9bf9c99
Automatically enable portable-atomic when required (#17570)
# Objective

- Contributes to #15460
- Reduce quantity and complexity of feature gates across Bevy

## Solution

- Used `target_has_atomic` configuration variable to automatically
detect impartial atomic support and automatically switch to
`portable-atomic` over the standard library on an as-required basis.

## Testing

- CI

## Notes

To explain the technique employed here, consider getting `Arc` either
from `alloc::sync` _or_ `portable-atomic-util`. First, we can inspect
the `alloc` crate to see that you only have access to `Arc` _if_
`target_has_atomic = "ptr"`. We add a target dependency for this
particular configuration _inverted_:

```toml
[target.'cfg(not(target_has_atomic = "ptr"))'.dependencies]
portable-atomic-util = { version = "0.2.4", default-features = false }
```

This ensures we only have the dependency when it is needed, and it is
entirely excluded from the dependency graph when it is not. Next, we
adjust our configuration flags to instead of checking for `feature =
"portable-atomic"` to instead check for `target_has_atomic = "ptr"`:

```rust
// `alloc` feature flag hidden for brevity

#[cfg(not(target_has_atomic = "ptr"))]
use portable_atomic_util as arc;

#[cfg(target_has_atomic = "ptr")]
use alloc::sync as arc;

pub use arc::{Arc, Weak};
```

The benefits of this technique are three-fold:

1. For platforms without full atomic support, the functionality is
enabled automatically.
2. For platforms with atomic support, the dependency is never included,
even if a feature was enabled using `--all-features` (for example)
3. The `portable-atomic` feature no longer needs to virally spread to
all user-facing crates, it's instead something handled within
`bevy_platform_support` (with some extras where other dependencies also
need their features enabled).
2025-02-24 20:52:46 +00:00
andriyDev
7f14581495
Use explicitly added ApplyDeferred stages when computing automatically inserted sync points. (#16782)
# Objective

- The previous implementation of automatically inserting sync points did
not consider explicitly added sync points. This created additional sync
points. For example:

```
A-B
C-D-E
```

If `A` and `B` needed a sync point, and `D` was an `ApplyDeferred`, an
additional sync point would be generated between `A` and `B`.

```
A-D2-B
C-D -E
```

This can result in the following system ordering:
```
A-D2-(B-C)-D-E
```
Where only `B` and `C` run in parallel. If we could reuse `D` as the
sync point, we would get the following ordering:
```
(A-C)-D-(B-E)
```
Now we have two more opportunities for parallelism!

## Solution

- In the first pass, we:
    - Compute the number of sync points before each node
- This was already happening but now we consider `ApplyDeferred` nodes
as creating a sync point.
- Pick an arbitrary explicit `ApplyDeferred` node for each "sync point
index" that we can (some required sync points may be missing!)
- In the second pass, we:
- For each edge, if two nodes have a different number of sync points
before them then there must be a sync point between them.
- Look for an explicit `ApplyDeferred`. If one exists, use it as the
sync point.
    - Otherwise, generate a new sync point.

I believe this should also gracefully handle changes to the
`ScheduleGraph`. Since automatically inserted sync points are inserted
as systems, they won't look any different to explicit sync points, so
they are also candidates for "reusing" sync points.

One thing this solution does not handle is "deduping" sync points. If
you add 10 sync points explicitly, there will be at least 10 sync
points. You could keep track of all the sync points at the same
"distance" and then hack apart the graph to dedup those, but that could
be a follow-up step (and it's more complicated since you have to worry
about transferring edges between nodes).

## Testing

- Added a test to test the feature.
-  The existing tests from all our crates still pass.

## Showcase

- Automatically inserted sync points can now reuse explicitly inserted
`ApplyDeferred` systems! Previously, Bevy would add new sync points
between systems, ignoring the explicitly added sync points. This would
reduce parallelism of systems in some situations. Now, the parallelism
has been improved!
2025-02-24 20:51:34 +00:00
Zachary Harrold
5241e09671
Upgrade to Rust Edition 2024 (#17967)
# Objective

- Fixes #17960

## Solution

- Followed the [edition upgrade
guide](https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html)

## Testing

- CI

---

## Summary of Changes

### Documentation Indentation

When using lists in documentation, proper indentation is now linted for.
This means subsequent lines within the same list item must start at the
same indentation level as the item.

```rust
/* Valid */
/// - Item 1
///   Run-on sentence.
/// - Item 2
struct Foo;

/* Invalid */
/// - Item 1
///     Run-on sentence.
/// - Item 2
struct Foo;
```

### Implicit `!` to `()` Conversion

`!` (the never return type, returned by `panic!`, etc.) no longer
implicitly converts to `()`. This is particularly painful for systems
with `todo!` or `panic!` statements, as they will no longer be functions
returning `()` (or `Result<()>`), making them invalid systems for
functions like `add_systems`. The ideal fix would be to accept functions
returning `!` (or rather, _not_ returning), but this is blocked on the
[stabilisation of the `!` type
itself](https://doc.rust-lang.org/std/primitive.never.html), which is
not done.

The "simple" fix would be to add an explicit `-> ()` to system
signatures (e.g., `|| { todo!() }` becomes `|| -> () { todo!() }`).
However, this is _also_ banned, as there is an existing lint which (IMO,
incorrectly) marks this as an unnecessary annotation.

So, the "fix" (read: workaround) is to put these kinds of `|| -> ! { ...
}` closuers into variables and give the variable an explicit type (e.g.,
`fn()`).

```rust
// Valid
let system: fn() = || todo!("Not implemented yet!");
app.add_systems(..., system);

// Invalid
app.add_systems(..., || todo!("Not implemented yet!"));
```

### Temporary Variable Lifetimes

The order in which temporary variables are dropped has changed. The
simple fix here is _usually_ to just assign temporaries to a named
variable before use.

### `gen` is a keyword

We can no longer use the name `gen` as it is reserved for a future
generator syntax. This involved replacing uses of the name `gen` with
`r#gen` (the raw-identifier syntax).

### Formatting has changed

Use statements have had the order of imports changed, causing a
substantial +/-3,000 diff when applied. For now, I have opted-out of
this change by amending `rustfmt.toml`

```toml
style_edition = "2021"
```

This preserves the original formatting for now, reducing the size of
this PR. It would be a simple followup to update this to 2024 and run
`cargo fmt`.

### New `use<>` Opt-Out Syntax

Lifetimes are now implicitly included in RPIT types. There was a handful
of instances where it needed to be added to satisfy the borrow checker,
but there may be more cases where it _should_ be added to avoid
breakages in user code.

### `MyUnitStruct { .. }` is an invalid pattern

Previously, you could match against unit structs (and unit enum
variants) with a `{ .. }` destructuring. This is no longer valid.

### Pretty much every use of `ref` and `mut` are gone

Pattern binding has changed to the point where these terms are largely
unused now. They still serve a purpose, but it is far more niche now.

### `iter::repeat(...).take(...)` is bad

New lint recommends using the more explicit `iter::repeat_n(..., ...)`
instead.

## Migration Guide

The lifetimes of functions using return-position impl-trait (RPIT) are
likely _more_ conservative than they had been previously. If you
encounter lifetime issues with such a function, please create an issue
to investigate the addition of `+ use<...>`.

## Notes

- Check the individual commits for a clearer breakdown for what
_actually_ changed.

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>
2025-02-24 03:54:47 +00:00
JaySpruce
283654cf4d
Small Commands error handling cleanup (#17904)
- Remove references to the short-lived `CommandError` type.
- Add a sentence to the explanation of error handlers.
- Clean up spacing/linebreaks.
- Use `where` notation for command-related trait `impl`s to make the big
ones easier to parse.
2025-02-23 22:41:43 +00:00
AlephCubed
5f86668bbb
Renamed EventWriter::send methods to write. (#17977)
Fixes #17856.

## Migration Guide
- `EventWriter::send` has been renamed to `EventWriter::write`.
- `EventWriter::send_batch` has been renamed to
`EventWriter::write_batch`.
- `EventWriter::send_default` has been renamed to
`EventWriter::write_default`.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
2025-02-23 21:18:52 +00:00
DragonGamesStudios
a7cb061d6c
Use fully qualified syntax in assertions. (#17936)
# Objective

Fix #17924 

## Solution

Use fully qualified syntax (`usize::from` rather than `.into()`).

## Testing

Ran a build for the platform specified in the issue.

---------

Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2025-02-22 01:58:54 +00:00
Christian Hughes
052b9d8261
Fix issue with define_label! instantiation in a 3rd party crate (#17958)
# Objective

Calling `define_label!` in a `no_std` 3rd party crate currently requires
the user to import `Box` themselves due to a non-fully-specified
reference to `Box`.

## Solution

Add a fully specified path for `Box` in the one location necessary, to
match all of the other cases.
2025-02-21 06:13:36 +00:00
Alice Cecile
be3c6f7578
Improve the docs for ChildOf and Children (#17886)
# Context

Renaming `Parent` to `ChildOf` in #17247 has been contentious. While
those users concerns are valid (especially around legibility of code
IMO!), @cart [has
decided](https://discord.com/channels/691052431525675048/749335865876021248/1340434322833932430)
to stick with the new name.

> In general this conversation is unsurprising to me, as it played out
essentially the same way when I asked for opinions in my PR. There are
strong opinions on both sides. Everyone is right in their own way.
> 
> I chose ChildOf for the following reasons:
> 
> 1. I think it derives naturally from the system we have built, the
concepts we have chosen, and how we generally name the types that
implement a trait in Rust. This is the name of the type implementing
Relationship. We are adding that Relationship component to a given
entity (whether it "is" the relationship or "has" the relationship is
kind of immaterial ... we are naming the relationship that it "is" or
"has"). What is the name of the relationship that a child has to its
parent? It is a "child" of the parent of course!
> 2. In general the non-parent/child relationships I've seen in the wild
generally benefit from (or need to) use the naming convention in (1)
(aka calling the Relationship the name of the relationship the entity
has). Many relationships don't have an equivalent to the Parent/Child
name concept.
> 3. I do think we could get away with using (1) for pretty much
everything else and special casing Parent/Children. But by embracing the
naming convention, we help establish that this is in fact a pattern, and
we help prime people to think about these things in a consistent way.
Consistency and predictability is a generally desirable property. And
for something as divisive and polarizing as relationship naming, I think
drawing a hard line in the sand is to the benefit of the community as a
whole.
> 4. I believe the fact that we dont see as much of the XOf naming style
elsewhere is to our benefit. When people see things in that style, they
are primed to think of them as relationships (after some exposure to
Bevy and the ecosystem). I consider this a useful hint.
> 5. Most of the practical confusion from using ChildOf seems to be from
calling the value of the target field we read from the relationship
child_of. The name of the target field should be parent (we could even
consider renaming child_of.0 to child_of.parent for clarity). I suspect
that existing Bevy users renaming their existing code will feel the most
friction here, as this requires a reframing. Imo it is natural and
expected to receive pushback from these users hitting this case.

## Objective

The new documentation doesn't do a particularly good job at quickly
explaining the meaning of each component or how to work with them;
making a tricky migration more painful and slowing down new users as
they learn about some of the most fundamental types in Bevy.

## Solution

1. Clearly explain what each component does in the very first line,
assuming no background knowledge. This is the first relationships that
99% of users will encounter, so explaining that they are relationships
is unhelpful as an introduction.
2. Add doc aliases for the rejected `IsParent`/`IsChild`/`Parent` names,
to improve autocomplete and doc searching.
3. Do some assorted docs cleanup while we're here.

---------

Co-authored-by: Eagster <79881080+ElliottjPierce@users.noreply.github.com>
2025-02-17 01:46:11 +00:00
JaySpruce
ee44560523
Add EntityDoesNotExistError, replace cases of Entity as an error, do some easy Resultification (#17855)
## Objective
There's no general error for when an entity doesn't exist, and some
methods are going to need one when they get Resultified. The closest
thing is `EntityFetchError`, but that error has a slightly more specific
purpose.

## Solution
- Added `EntityDoesNotExistError`.
  - Contains `Entity` and `EntityDoesNotExistDetails`.
- Changed `EntityFetchError` and `QueryEntityError`:
- Changed `NoSuchEntity` variant to wrap `EntityDoesNotExistError` and
renamed the variant to `EntityDoesNotExist`.
- Renamed `EntityFetchError` to `EntityMutableFetchError` to make its
purpose clearer.
- Renamed `TryDespawnError` to `EntityDespawnError` to make it more
general.
- Changed `World::inspect_entity` to return `Result<[ok],
EntityDoesNotExistError>` instead of panicking.
- Changed `World::get_entity` and `WorldEntityFetch::fetch_ref` to
return `Result<[ok], EntityDoesNotExistError>` instead of `Result<[ok],
Entity>`.
- Changed `UnsafeWorldCell::get_entity` to return
`Result<UnsafeEntityCell, EntityDoesNotExistError>` instead of
`Option<UnsafeEntityCell>`.

## Migration Guide
- `World::inspect_entity` now returns `Result<impl Iterator<Item =
&ComponentInfo>, EntityDoesNotExistError>` instead of `impl
Iterator<Item = &ComponentInfo>`.
- `World::get_entity` now returns `EntityDoesNotExistError` as an error
instead of `Entity`. You can still access the entity's ID through the
error's `entity` field.
- `UnsafeWorldCell::get_entity` now returns `Result<UnsafeEntityCell,
EntityDoesNotExistError>` instead of `Option<UnsafeEntityCell>`.
2025-02-16 21:59:46 +00:00
Chris Russell
794bf6a332
Move implementations of Query methods from QueryState to Query. (#17822)
# Objective

Simplify the API surface by removing duplicated functionality between
`Query` and `QueryState`.

Reduce the amount of `unsafe` code required in `QueryState`.  

This is a follow-up to #15858.

## Solution

Move implementations of `Query` methods from `QueryState` to `Query`.
Instead of the original methods being on `QueryState`, with `Query`
methods calling them by passing the individual parameters, the original
methods are now on `Query`, with `QueryState` methods calling them by
constructing a `Query`.

This also adds two `_inner` methods that were missed in #15858:
`iter_many_unique_inner` and `single_inner`.

One goal here is to be able to deprecate and eventually remove many of
the methods on `QueryState`, reducing the overall API surface. (I
expected to do that in this PR, but this change was large enough on its
own!) Now that the `QueryState` methods each consist of a simple
expression like `self.query(world).get_inner(entity)`, a future PR can
deprecate some or all of them with simple migration instructions.

The other goal is to reduce the amount of `unsafe` code. The current
implementation of a read-only method like `QueryState::get` directly
calls the `unsafe fn get_unchecked_manual` and needs to repeat the proof
that `&World` has enough access. With this change, `QueryState::get` is
entirely safe code, with the proof that `&World` has enough access done
by the `query()` method and shared across all read-only operations.

## Future Work

The next step will be to mark the `QueryState` methods as
`#[deprecated]` and migrate callers to the methods on `Query`.
2025-02-16 19:57:43 +00:00
Chris Russell
0a32450715
Support using FilteredResources with ReflectResource. (#15624)
# Objective

Support accessing resources using reflection when using
`FilteredResources` in a dynamic system. This is similar to how
components can be queried using reflection when using
`FilteredEntityRef|Mut`.

## Solution

Change `ReflectResource` from taking `&World` and `&mut World` to taking
`impl Into<FilteredResources>` and `impl Into<FilteredResourcesMut>`,
similar to how `ReflectComponent` takes `impl Into<FilteredEntityRef>`
and `impl Into<FilteredEntityMut>`. There are `From` impls that ensure
code passing `&World` and `&mut World` continues to work as before.

## Migration Guide

If you are manually creating a `ReflectComponentFns` struct, the
`reflect` function now takes `FilteredResources` instead `&World`, and
there is a new `reflect_mut` function that takes `FilteredResourcesMut`.
2025-02-16 19:56:19 +00:00
Vic
05e61d64f5
implement par_iter_many and par_iter_many_unique (#17815)
# Objective

Continuation of #16547.

We do not yet have parallel versions of `par_iter_many` and
`par_iter_many_unique`. It is currently very painful to try and use
parallel iteration over entity lists. Even if a list is not long, each
operation might still be very expensive, and worth parallelizing.
Plus, it has been requested several times!

## Solution

Once again, we implement what we lack!

These parallel iterators collect their input entity list into a
`Vec`/`UniqueEntityVec`, then chunk that over the available threads,
inspired by the original `par_iter`.

Since no order guarantee is given to the caller, we could sort the input
list according to `EntityLocation`, but that would likely only be worth
it for very large entity lists.

There is some duplication which could likely be improved, but I'd like
to leave that for a follow-up.

## Testing

The doc tests on `for_each_init` of `QueryParManyIter` and
`QueryParManyUniqueIter`.
2025-02-13 19:49:41 +00:00
Rob Parrett
2760692f88
Update typos to 1.29.6 (#17850)
# Objective

Update typos, fix new typos.

1.29.6 was just released to fix an
[issue](https://github.com/crate-ci/typos/issues/1228) where January's
corrections were not included in the binaries for the last release.

Reminder: typos can be tossed in the monthly [non-critical corrections
issue](https://github.com/crate-ci/typos/issues/1221).

## Solution

I chose to allow `implementors`, because a good argument seems to be
being made [here](https://github.com/crate-ci/typos/issues/1226) and
there is now a PR to address that.

## Discussion

Should I exclude `bevy_mikktspace`?

At one point I think we had an informal policy of "don't mess with
mikktspace until https://github.com/bevyengine/bevy/pull/9050 is merged"
but it doesn't seem like that is likely to be merged any time soon.

I think these particular corrections in mikktspace are fine because
- The same typo mistake seems to have been fixed in that PR
- The entire file containing these corrections was deleted in that PR

## Typo of the Month

correspindong -> corresponding
2025-02-13 19:44:47 +00:00
Chris Russell
62c1812e72
Shorten the 'world lifetime returned from QueryLens::query(). (#17694)
# Objective

Fix unsoundness introduced by #15858. `QueryLens::query()` would hand
out a `Query` with the full `'w` lifetime, and the new `_inner` methods
would let the results outlive the `Query`. This could be used to create
aliasing mutable references, like

```rust
fn bad<'w>(mut lens: QueryLens<'w, EntityMut>, entity: Entity) {
    let one: EntityMut<'w> = lens.query().get_inner(entity).unwrap();
    let two: EntityMut<'w> = lens.query().get_inner(entity).unwrap();
    assert!(one.entity() == two.entity());
}
```

Fixes #17693 

## Solution

Restrict the `'world` lifetime in the `Query` returned by
`QueryLens::query()` to `'_`, the lifetime of the borrow of the
`QueryLens`.

The model here is that `Query<'w, 's, D, F>` and `QueryLens<'w, D, F>`
have permission to access their components for the lifetime `'w`. So
going from `&'a mut QueryLens<'w>` to `Query<'w, 'a>` would borrow the
permission only for the `'a` lifetime, but incorrectly give it out for
the full `'w` lifetime.

To handle any cases where users were calling `get_inner()` or
`iter_inner()` on the `Query` and expecting the full `'w` lifetime, we
introduce a new `QueryLens::query_inner()` method. This is only valid
for `ReadOnlyQueryData`, so it may safely hand out a copy of the
permission for the full `'w` lifetime. Since `get_inner()` and
`iter_inner()` were only valid on `ReadOnlyQueryData` prior to #15858,
that should cover any uses that relied on the longer lifetime.

## Migration Guide

Users of `QueryLens::query()` who were calling `get_inner()` or
`iter_inner()` will need to replace the call with
`QueryLens::query_inner()`.
2025-02-12 22:41:02 +00:00
Andreas Monitzer
267a0d003c
Add ComponentId-taking functions to Entity{Ref,Mut}Except to mirror FilteredEntity{Ref,Mut} (#17800)
# Objective

Related to #17784. The ticket is actually about just getting rid of
`Entity{Ref,Mut}Except` in favor of `FilteredEntity{Ref,Mut}`, but I got
told the unification of Entity types is a bigger endeavor that has been
going on for a while now (as the "Pointing Fingers" working group) and I
should just add the functions I actually need in the meantime.

## Solution

This PR adds all of the functions necessary to access components by
TypeId or ComponentId instead of static types.

## Testing

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

Haven't tested it yet, but the changes are mostly copy/paste from other
implementations in the same file, since there is a lot of duplicated
functionality there.

## Not a Migration Guide

There shouldn't be any breaking changes, it's just a few new functions
on existing types.

I had to shuffle around the lifetimes in `From<&EntityMutExcept<'a, B>>
for EntityRefExcept<'a, B>` (originally it was `From<&'a
EntityMutExcept<'_, B>> for EntityRefExcept<'_, B>`) to make the borrow
checker happy, but I don't think that this should have an impact on user
code (correct me if I'm wrong).
2025-02-12 18:34:35 +00:00
Vic
153ce468ef
implement iterators that yield UniqueEntitySlice (#17796)
# Objective

Continuation of #17589 and #16547.

Slices have several methods that return iterators which themselves yield
slices, which we have not yet implemented.
An example use is `par_iter_many` style logic.

## Solution

Their implementation is rather straightforward, we simply delegate all
impls to `[T]`.
The resulting iterator types need their own wrappers in the form of
`UniqueEntitySliceIter` and `UniqueEntitySliceIterMut`.

We also add three free functions that cast slices of entity slices to
slices of `UniqueEntitySlice`.
These three should be sufficient, though infinite nesting is achievable
with a trait (like `TrustedEntityBorrow` works over infinite reference
nesting), should the need ever arise.
2025-02-12 03:59:56 +00:00
Jean Mertz
7d8504f30e
feat(ecs): implement fallible observer systems (#17731)
This commit builds on top of the work done in #16589 and #17051, by
adding support for fallible observer systems.

As with the previous work, the actual results of the observer system are
suppressed for now, but the intention is to provide a way to handle
errors in a global way.

Until then, you can use a `PipeSystem` to manually handle results.

---------

Signed-off-by: Jean Mertz <git@jeanmertz.com>
2025-02-11 22:15:43 +00:00
Periwink
d6725d3b1b
Expose method to update the internal ticks of Ref and Mut (#17716)
## What problem does this solve or what need does it fill?

There are some situations
(https://github.com/bevyengine/bevy/issues/13735) where the ticks that
are present inside `Ref` are incorrect, for example if `Ref` is created
outside of a `SystemParam`.
I still want to use `Ref` because it has convenient `is_added` and
`is_changed` methods.

My current solution is to build my own `Ref` by copy-pasting most the
bevy code to do that via something like
```rust
/// This method is necessary because there is no easy way to 
pub(crate) fn get_ref<C: Component>(
    world: &World,
    entity: Entity,
    last_run: Tick,
    this_run: Tick,
) -> Ref<C> {
    unsafe {
        let component_id = world
            .components()
            .get_id(TypeId::of::<C>())
            .unwrap_unchecked();
        let world = world.as_unsafe_world_cell_readonly();
        let entity_cell = world.get_entity(entity).unwrap_unchecked();
        get_component_and_ticks(
            world,
            component_id,
            C::STORAGE_TYPE,
            entity,
            entity_cell.location(),
        )
        .map(|(value, cells, _caller)| {
            Ref::new(
                value.deref::<C>(),
                cells.added.deref(),
                cells.changed.deref(),
                last_run,
                this_run,
                #[cfg(feature = "track_location")]
                _caller.deref(),
            )
        })
        .unwrap_unchecked()
    }
}

// Utility function to return
#[inline]
unsafe fn get_component_and_ticks(
    world: UnsafeWorldCell<'_>,
    component_id: ComponentId,
    storage_type: StorageType,
    entity: Entity,
    location: EntityLocation,
) -> Option<(Ptr<'_>, TickCells<'_>, MaybeUnsafeCellLocation<'_>)> {
    match storage_type {
        StorageType::Table => {
            let table = unsafe { world.storages().tables.get(location.table_id) }?;

            // SAFETY: archetypes only store valid table_rows and caller ensure aliasing rules
            Some((
                table.get_component(component_id, location.table_row)?,
                TickCells {
                    added: table
                        .get_added_tick(component_id, location.table_row)
                        .unwrap_unchecked(),
                    changed: table
                        .get_changed_tick(component_id, location.table_row)
                        .unwrap_unchecked(),
                },
                #[cfg(feature = "track_location")]
                table
                    .get_changed_by(component_id, location.table_row)
                    .unwrap_unchecked(),
                #[cfg(not(feature = "track_location"))]
                (),
            ))
        }
        StorageType::SparseSet => {
            let storage = unsafe { world.storages() }.sparse_sets.get(component_id)?;
            storage.get_with_ticks(entity)
        }
    }
}
```

It would be very convenient if instead bevy exposed a way to create a
`Ref` object with custom `last_run` and `this_run` ticks.
This PR does this by exposing a function to overwrite the `last_run` and
`this_run` ticks.
(Same with `Mut`)

I am ok with marking the method unsafe or risky if it's deemed to risky
for end-users.
2025-02-11 19:00:13 +00:00
Jean Mertz
fd67ca7eb0
feat(ecs): configurable error handling for fallible systems (#17753)
You can now configure error handlers for fallible systems. These can be
configured on several levels:

- Globally via `App::set_systems_error_handler`
- Per-schedule via `Schedule::set_error_handler`
- Per-system via a piped system (this is existing functionality)

The default handler of panicking on error keeps the same behavior as
before this commit.

The "fallible_systems" example demonstrates the new functionality.

This builds on top of #17731, #16589, #17051.

---------

Signed-off-by: Jean Mertz <git@jeanmertz.com>
2025-02-11 18:36:08 +00:00
Alice Cecile
fcc77fe3d6
Allow users to register their own disabling components / default query filters (#17768)
# Objective

Currently, default query filters, as added in #13120 / #17514 are
hardcoded to only use a single query filter.

This is limiting, as multiple distinct disabling components can serve
important distinct roles. I ran into this limitation when experimenting
with a workflow for prefabs, which don't represent the same state as "an
entity which is temporarily nonfunctional".

## Solution

1. Change `DefaultQueryFilters` to store a SmallVec of ComponentId,
rather than an Option.
2. Expose methods on `DefaultQueryFilters`, `World` and `App` to
actually configure this.
3. While we're here, improve the docs, write some tests, make use of
FromWorld and make some method names more descriptive.

## Follow-up

I'm not convinced that supporting sparse set disabling components is
useful, given the hit to iteration performance and runtime checks
incurred. That's disjoint from this PR though, so I'm not doing it here.
The existing warnings are fine for now.

## Testing

I've added both a doc test and an mid-level unit test to verify that
this works!
2025-02-11 18:25:32 +00:00
person93
575f66504b
Silence deprecation warning in Bundle derive macro (#17369) (#17790)
# Objective

- Fixes #17369

## Solution

- Add `#[allow(deprecated)]` to the generated code.
2025-02-11 00:56:09 +00:00
Chris Russell
c34a2c2fba
Query::get_many should not check for duplicates (#17724)
# Objective

Restore the behavior of `Query::get_many` prior to #15858.  

When passed duplicate `Entity`s, `get_many` is supposed to return
results for all of them, since read-only queries don't alias. However,
#15858 merged the implementation with `get_many_mut` and caused it to
return `QueryEntityError::AliasedMutability`.

## Solution

Introduce a new `Query::get_many_readonly` method that consumes the
`Query` like `get_many_inner`, but that is constrained to `D:
ReadOnlyQueryData` so that it can skip the aliasing check. Implement
`Query::get_many` in terms of that new method. Add a test, and a comment
explaining why it doesn't match the pattern of the other `&self`
methods.
2025-02-10 22:07:15 +00:00
urben1680
7f9588d4c6
Fix documentation of Entities::get (#17721)
This method returns `None` if `meta.location.archetype_id` is
`ArchetypeId::INVALID`.
`EntityLocation::INVALID.archetype_id` is `ArchetypeId::INVALID`.
Therefore this method cannot return `Some(EntityLocation::INVALID)`.
Linking to it in the docs is futile anyway as that constant is not
public.
2025-02-10 22:05:05 +00:00
Chris Russell
eee7fd5b3e
Encapsulate cfg(feature = "track_location") in a type. (#17602)
# Objective

Eliminate the need to write `cfg(feature = "track_location")` every time
one uses an API that may use location tracking. It's verbose, and a
little intimidating. And it requires code outside of `bevy_ecs` that
wants to use location tracking needs to either unconditionally enable
the feature, or include conditional compilation of its own. It would be
good for users to be able to log locations when they are available
without needing to add feature flags to their own crates.

Reduce the number of cases where code compiles with the `track_location`
feature enabled, but not with it disabled, or vice versa. It can be hard
to remember to test it both ways!

Remove the need to store a `None` in `HookContext` when the
`track_location` feature is disabled.

## Solution

Create an `MaybeLocation<T>` type that contains a `T` if the
`track_location` feature is enabled, and is a ZST if it is not. The
overall API is similar to `Option`, but whether the value is `Some` or
`None` is set at compile time and is the same for all values.

Default `T` to `&'static Location<'static>`, since that is the most
common case.

Remove all `cfg(feature = "track_location")` blocks outside of the
implementation of that type, and instead call methods on it.

When `track_location` is disabled, `MaybeLocation` is a ZST and all
methods are `#[inline]` and empty, so they should be entirely removed by
the compiler. But the code will still be visible to the compiler and
checked, so if it compiles with the feature disabled then it should also
compile with it enabled, and vice versa.

## Open Questions

Where should these types live? I put them in `change_detection` because
that's where the existing `MaybeLocation` types were, but we now use
these outside of change detection.

While I believe that the compiler should be able to remove all of these
calls, I have not actually tested anything. If we want to take this
approach, what testing is required to ensure it doesn't impact
performance?

## Migration Guide

Methods like `Ref::changed_by()` that return a `&'static
Location<'static>` will now be available even when the `track_location`
feature is disabled, but they will return a new `MaybeLocation` type.
`MaybeLocation` wraps a `&'static Location<'static>` when the feature is
enabled, and is a ZST when the feature is disabled.

Existing code that needs a `&Location` can call `into_option().unwrap()`
to recover it. Many trait impls are forwarded, so if you only need
`Display` then no changes will be necessary.

If that code was conditionally compiled, you may instead want to use the
methods on `MaybeLocation` to remove the need for conditional
compilation.

Code that constructs a `Ref`, `Mut`, `Res`, or `ResMut` will now need to
provide location information unconditionally. If you are creating them
from existing Bevy types, you can obtain a `MaybeLocation` from methods
like `Table::get_changed_by_slice_for()` or
`ComponentSparseSet::get_with_ticks`. Otherwise, you will need to store
a `MaybeLocation` next to your data and use methods like `as_ref()` or
`as_mut()` to obtain wrapped references.
2025-02-10 21:21:20 +00:00
Carter Anderson
ea578415e1
Improved Spawn APIs and Bundle Effects (#17521)
## Objective

A major critique of Bevy at the moment is how boilerplatey it is to
compose (and read) entity hierarchies:

```rust
commands
    .spawn(Foo)
    .with_children(|p| {
        p.spawn(Bar).with_children(|p| {
            p.spawn(Baz);
        });
        p.spawn(Bar).with_children(|p| {
            p.spawn(Baz);
        });
    });
```

There is also currently no good way to statically define and return an
entity hierarchy from a function. Instead, people often do this
"internally" with a Commands function that returns nothing, making it
impossible to spawn the hierarchy in other cases (direct World spawns,
ChildSpawner, etc).

Additionally, because this style of API results in creating the
hierarchy bits _after_ the initial spawn of a bundle, it causes ECS
archetype changes (and often expensive table moves).

Because children are initialized after the fact, we also can't count
them to pre-allocate space. This means each time a child inserts itself,
it has a high chance of overflowing the currently allocated capacity in
the `RelationshipTarget` collection, causing literal worst-case
reallocations.

We can do better!

## Solution

The Bundle trait has been extended to support an optional
`BundleEffect`. This is applied directly to World immediately _after_
the Bundle has fully inserted. Note that this is
[intentionally](https://github.com/bevyengine/bevy/discussions/16920)
_not done via a deferred Command_, which would require repeatedly
copying each remaining subtree of the hierarchy to a new command as we
walk down the tree (_not_ good performance).

This allows us to implement the new `SpawnRelated` trait for all
`RelationshipTarget` impls, which looks like this in practice:

```rust
world.spawn((
    Foo,
    Children::spawn((
        Spawn((
            Bar,
            Children::spawn(Spawn(Baz)),
        )),
        Spawn((
            Bar,
            Children::spawn(Spawn(Baz)),
        )),
    ))
))
```

`Children::spawn` returns `SpawnRelatedBundle<Children, L:
SpawnableList>`, which is a `Bundle` that inserts `Children`
(preallocated to the size of the `SpawnableList::size_hint()`).
`Spawn<B: Bundle>(pub B)` implements `SpawnableList` with a size of 1.
`SpawnableList` is also implemented for tuples of `SpawnableList` (same
general pattern as the Bundle impl).

There are currently three built-in `SpawnableList` implementations:

```rust
world.spawn((
    Foo,
    Children::spawn((
        Spawn(Name::new("Child1")),   
        SpawnIter(["Child2", "Child3"].into_iter().map(Name::new),
        SpawnWith(|parent: &mut ChildSpawner| {
            parent.spawn(Name::new("Child4"));
            parent.spawn(Name::new("Child5"));
        })
    )),
))
```

We get the benefits of "structured init", but we have nice flexibility
where it is required!

Some readers' first instinct might be to try to remove the need for the
`Spawn` wrapper. This is impossible in the Rust type system, as a tuple
of "child Bundles to be spawned" and a "tuple of Components to be added
via a single Bundle" is ambiguous in the Rust type system. There are two
ways to resolve that ambiguity:

1. By adding support for variadics to the Rust type system (removing the
need for nested bundles). This is out of scope for this PR :)
2. Using wrapper types to resolve the ambiguity (this is what I did in
this PR).

For the single-entity spawn cases, `Children::spawn_one` does also
exist, which removes the need for the wrapper:

```rust
world.spawn((
    Foo,
    Children::spawn_one(Bar),
))
```

## This works for all Relationships

This API isn't just for `Children` / `ChildOf` relationships. It works
for any relationship type, and they can be mixed and matched!

```rust
world.spawn((
    Foo,
    Observers::spawn((
        Spawn(Observer::new(|trigger: Trigger<FuseLit>| {})),
        Spawn(Observer::new(|trigger: Trigger<Exploded>| {})),
    )),
    OwnerOf::spawn(Spawn(Bar))
    Children::spawn(Spawn(Baz))
))
```

## Macros

While `Spawn` is necessary to satisfy the type system, we _can_ remove
the need to express it via macros. The example above can be expressed
more succinctly using the new `children![X]` macro, which internally
produces `Children::spawn(Spawn(X))`:

```rust
world.spawn((
    Foo,
    children![
        (
            Bar,
            children![Baz],
        ),
        (
            Bar,
            children![Baz],
        ),
    ]
))
```

There is also a `related!` macro, which is a generic version of the
`children!` macro that supports any relationship type:

```rust
world.spawn((
    Foo,
    related!(Children[
        (
            Bar,
            related!(Children[Baz]),
        ),
        (
            Bar,
            related!(Children[Baz]),
        ),
    ])
))
```

## Returning Hierarchies from Functions

Thanks to these changes, the following pattern is now possible:

```rust
fn button(text: &str, color: Color) -> impl Bundle {
    (
        Node {
            width: Val::Px(300.),
            height: Val::Px(100.),
            ..default()
        },
        BackgroundColor(color),
        children![
            Text::new(text),
        ]
    )
}

fn ui() -> impl Bundle {
    (
        Node {
            width: Val::Percent(100.0),
            height: Val::Percent(100.0),
            ..default(),
        },
        children![
            button("hello", BLUE),
            button("world", RED),
        ]
    )
}

// spawn from a system
fn system(mut commands: Commands) {
    commands.spawn(ui());
}

// spawn directly on World
world.spawn(ui());
```

## Additional Changes and Notes

* `Bundle::from_components` has been split out into
`BundleFromComponents::from_components`, enabling us to implement
`Bundle` for types that cannot be "taken" from the ECS (such as the new
`SpawnRelatedBundle`).
* The `NoBundleEffect` trait (which implements `BundleEffect`) is
implemented for empty tuples (and tuples of empty tuples), which allows
us to constrain APIs to only accept bundles that do not have effects.
This is critical because the current batch spawn APIs cannot efficiently
apply BundleEffects in their current form (as doing so in-place could
invalidate the cached raw pointers). We could consider allocating a
buffer of the effects to be applied later, but that does have
performance implications that could offset the balance and value of the
batched APIs (and would likely require some refactors to the underlying
code). I've decided to be conservative here. We can consider relaxing
that requirement on those APIs later, but that should be done in a
followup imo.
* I've ported a few examples to illustrate real-world usage. I think in
a followup we should port all examples to the `children!` form whenever
possible (and for cases that require things like SpawnIter, use the raw
APIs).
* Some may ask "why not use the `Relationship` to spawn (ex:
`ChildOf::spawn(Foo)`) instead of the `RelationshipTarget` (ex:
`Children::spawn(Spawn(Foo))`)?". That _would_ allow us to remove the
`Spawn` wrapper. I've explicitly chosen to disallow this pattern.
`Bundle::Effect` has the ability to create _significant_ weirdness.
Things in `Bundle` position look like components. For example
`world.spawn((Foo, ChildOf::spawn(Bar)))` _looks and reads_ like Foo is
a child of Bar. `ChildOf` is in Foo's "component position" but it is not
a component on Foo. This is a huge problem. Now that `Bundle::Effect`
exists, we should be _very_ principled about keeping the "weird and
unintuitive behavior" to a minimum. Things that read like components
_should be the components they appear to be".

## Remaining Work

* The macros are currently trivially implemented using macro_rules and
are currently limited to the max tuple length. They will require a
proc_macro implementation to work around the tuple length limit.

## Next Steps

* Port the remaining examples to use `children!` where possible and raw
`Spawn` / `SpawnIter` / `SpawnWith` where the flexibility of the raw API
is required.

## Migration Guide

Existing spawn patterns will continue to work as expected.

Manual Bundle implementations now require a `BundleEffect` associated
type. Exisiting bundles would have no bundle effect, so use `()`.
Additionally `Bundle::from_components` has been moved to the new
`BundleFromComponents` trait.

```rust
// Before
unsafe impl Bundle for X {
    unsafe fn from_components<T, F>(ctx: &mut T, func: &mut F) -> Self {
    }
    /* remaining bundle impl here */
}

// After
unsafe impl Bundle for X {
    type Effect = ();
    /* remaining bundle impl here */
}

unsafe impl BundleFromComponents for X {
    unsafe fn from_components<T, F>(ctx: &mut T, func: &mut F) -> Self {
    }
}
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
Co-authored-by: Emerson Coskey <emerson@coskey.dev>
2025-02-09 23:32:56 +00:00
newclarityex
c679b861d8
adds example for local defaults (#17751)
# Objective
Solves https://github.com/bevyengine/bevy/issues/17747.

## Solution

- Adds an example for creating a default value for Local.

## Testing

- Example code compiles and passes assertions.
2025-02-09 22:02:35 +00:00
raldone01
1b7db895b7
Harden proc macro path resolution and add integration tests. (#17330)
This pr uses the `extern crate self as` trick to make proc macros behave
the same way inside and outside bevy.

# Objective

- Removes noise introduced by `crate as` in the whole bevy repo.
- Fixes #17004.
- Hardens proc macro path resolution.

## TODO

- [x] `BevyManifest` needs cleanup.
- [x] Cleanup remaining `crate as`.
- [x] Add proper integration tests to the ci.

## Notes

- `cargo-manifest-proc-macros` is written by me and based/inspired by
the old `BevyManifest` implementation and
[`bkchr/proc-macro-crate`](https://github.com/bkchr/proc-macro-crate).
- What do you think about the new integration test machinery I added to
the `ci`?
  More and better integration tests can be added at a later stage.
The goal of these integration tests is to simulate an actual separate
crate that uses bevy. Ideally they would lightly touch all bevy crates.

## Testing

- Needs RA test
- Needs testing from other users
- Others need to run at least `cargo run -p ci integration-test` and
verify that they work.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-02-09 19:45:45 +00:00
François Mockers
7400e7adfd
Cleanup publish process (#17728)
# Objective

- publish script copy the license files to all subcrates, meaning that
all publish are dirty. this breaks git verification of crates
- the order and list of crates to publish is manually maintained,
leading to error. cargo 1.84 is more strict and the list is currently
wrong

## Solution

- duplicate all the licenses to all crates and remove the
`--allow-dirty` flag
- instead of a manual list of crates, get it from `cargo package
--workspace`
- remove the `--no-verify` flag to... verify more things?
2025-02-09 17:46:19 +00:00
Carter Anderson
3c8fae2390
Improved Entity Mapping and Cloning (#17687)
Fixes #17535

Bevy's approach to handling "entity mapping" during spawning and cloning
needs some work. The addition of
[Relations](https://github.com/bevyengine/bevy/pull/17398) both
[introduced a new "duplicate entities" bug when spawning scenes in the
scene system](#17535) and made the weaknesses of the current mapping
system exceedingly clear:

1. Entity mapping requires _a ton_ of boilerplate (implement or derive
VisitEntities and VisitEntitesMut, then register / reflect MapEntities).
Knowing the incantation is challenging and if you forget to do it in
part or in whole, spawning subtly breaks.
2. Entity mapping a spawned component in scenes incurs unnecessary
overhead: look up ReflectMapEntities, create a _brand new temporary
instance_ of the component using FromReflect, map the entities in that
instance, and then apply that on top of the actual component using
reflection. We can do much better.

Additionally, while our new [Entity cloning
system](https://github.com/bevyengine/bevy/pull/16132) is already pretty
great, it has some areas we can make better:

* It doesn't expose semantic info about the clone (ex: ignore or "clone
empty"), meaning we can't key off of that in places where it would be
useful, such as scene spawning. Rather than duplicating this info across
contexts, I think it makes more sense to add that info to the clone
system, especially given that we'd like to use cloning code in some of
our spawning scenarios.
* EntityCloner is currently built in a way that prioritizes a single
entity clone
* EntityCloner's recursive cloning is built to be done "inside out" in a
parallel context (queue commands that each have a clone of
EntityCloner). By making EntityCloner the orchestrator of the clone we
can remove internal arcs, improve the clarity of the code, make
EntityCloner mutable again, and simplify the builder code.
* EntityCloner does not currently take into account entity mapping. This
is necessary to do true "bullet proof" cloning, would allow us to unify
the per-component scene spawning and cloning UX, and ultimately would
allow us to use EntityCloner in place of raw reflection for scenes like
`Scene(World)` (which would give us a nice performance boost: fewer
archetype moves, less reflection overhead).

## Solution

### Improved Entity Mapping

First, components now have first-class "entity visiting and mapping"
behavior:

```rust
#[derive(Component, Reflect)]
#[reflect(Component)]
struct Inventory {
    size: usize,
    #[entities]
    items: Vec<Entity>,
}
```

Any field with the `#[entities]` annotation will be viewable and
mappable when cloning and spawning scenes.

Compare that to what was required before!

```rust
#[derive(Component, Reflect, VisitEntities, VisitEntitiesMut)]
#[reflect(Component, MapEntities)]
struct Inventory {
    #[visit_entities(ignore)]
    size: usize,
    items: Vec<Entity>,
}
```

Additionally, for relationships `#[entities]` is implied, meaning this
"just works" in scenes and cloning:

```rust
#[derive(Component, Reflect)]
#[relationship(relationship_target = Children)]
#[reflect(Component)]
struct ChildOf(pub Entity);
```

Note that Component _does not_ implement `VisitEntities` directly.
Instead, it has `Component::visit_entities` and
`Component::visit_entities_mut` methods. This is for a few reasons:

1. We cannot implement `VisitEntities for C: Component` because that
would conflict with our impl of VisitEntities for anything that
implements `IntoIterator<Item=Entity>`. Preserving that impl is more
important from a UX perspective.
2. We should not implement `Component: VisitEntities` VisitEntities in
the Component derive, as that would increase the burden of manual
Component trait implementors.
3. Making VisitEntitiesMut directly callable for components would make
it easy to invalidate invariants defined by a component author. By
putting it in the `Component` impl, we can make it harder to call
naturally / unavailable to autocomplete using `fn
visit_entities_mut(this: &mut Self, ...)`.

`ReflectComponent::apply_or_insert` is now
`ReflectComponent::apply_or_insert_mapped`. By moving mapping inside
this impl, we remove the need to go through the reflection system to do
entity mapping, meaning we no longer need to create a clone of the
target component, map the entities in that component, and patch those
values on top. This will make spawning mapped entities _much_ faster
(The default `Component::visit_entities_mut` impl is an inlined empty
function, so it will incur no overhead for unmapped entities).

### The Bug Fix

To solve #17535, spawning code now skips entities with the new
`ComponentCloneBehavior::Ignore` and
`ComponentCloneBehavior::RelationshipTarget` variants (note
RelationshipTarget is a temporary "workaround" variant that allows
scenes to skip these components. This is a temporary workaround that can
be removed as these cases should _really_ be using EntityCloner logic,
which should be done in a followup PR. When that is done,
`ComponentCloneBehavior::RelationshipTarget` can be merged into the
normal `ComponentCloneBehavior::Custom`).

### Improved Cloning

* `Option<ComponentCloneHandler>` has been replaced by
`ComponentCloneBehavior`, which encodes additional intent and context
(ex: `Default`, `Ignore`, `Custom`, `RelationshipTarget` (this last one
is temporary)).
* Global per-world entity cloning configuration has been removed. This
felt overly complicated, increased our API surface, and felt too
generic. Each clone context can have different requirements (ex: what a
user wants in a specific system, what a scene spawner wants, etc). I'd
prefer to see how far context-specific EntityCloners get us first.
* EntityCloner's internals have been reworked to remove Arcs and make it
mutable.
* EntityCloner is now directly stored on EntityClonerBuilder,
simplifying the code somewhat
* EntityCloner's "bundle scratch" pattern has been moved into the new
BundleScratch type, improving its usability and making it usable in
other contexts (such as future cross-world cloning code). Currently this
is still private, but with some higher level safe APIs it could be used
externally for making dynamic bundles
* EntityCloner's recursive cloning behavior has been "externalized". It
is now responsible for orchestrating recursive clones, meaning it no
longer needs to be sharable/clone-able across threads / read-only.
* EntityCloner now does entity mapping during clones, like scenes do.
This gives behavior parity and also makes it more generically useful.
* `RelatonshipTarget::RECURSIVE_SPAWN` is now
`RelationshipTarget::LINKED_SPAWN`, and this field is used when cloning
relationship targets to determine if cloning should happen recursively.
The new `LINKED_SPAWN` term was picked to make it more generically
applicable across spawning and cloning scenarios.

## Next Steps

* I think we should adapt EntityCloner to support cross world cloning. I
think this PR helps set the stage for that by making the internals
slightly more generalized. We could have a CrossWorldEntityCloner that
reuses a lot of this infrastructure.
* Once we support cross world cloning, we should use EntityCloner to
spawn `Scene(World)` scenes. This would yield significant performance
benefits (no archetype moves, less reflection overhead).

---------

Co-authored-by: eugineerd <70062110+eugineerd@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-02-06 22:13:41 +00:00
Zhixing Zhang
f2a65c2dd3
Schedule build pass (#11094)
# Objective

This is a follow up to #9822, which automatically adds sync points
during the Schedule build process.

However, the implementation in #9822 feels very "special case" to me. As
the number of things we want to do with the `Schedule` grows, we need a
modularized way to manage those behaviors. For example, in one of my
current experiments I want to automatically add systems to apply GPU
pipeline barriers between systems accessing GPU resources.

For dynamic modifications of the schedule, we mostly need these
capabilities:
- Storing custom data on schedule edges
- Storing custom data on schedule nodes
- Modify the schedule graph whenever it builds

These should be enough to allows us to add "hooks" to the schedule build
process for various reasons.

cc @hymm 

## Solution
This PR abstracts the process of schedule modification and created a new
trait, `ScheduleBuildPass`. Most of the logics in #9822 were moved to an
implementation of `ScheduleBuildPass`, `AutoInsertApplyDeferredPass`.

Whether a dependency edge should "ignore deferred" is now indicated by
the presence of a marker struct, `IgnoreDeferred`.

This PR has no externally visible effects. However, in a future PR I
propose to change the `before_ignore_deferred` and
`after_ignore_deferred` API into a more general form,
`before_with_options` and `after_with_options`.

```rs
schedule.add_systems(
    system.before_with_options(another_system, IgnoreDeferred)
);

schedule.add_systems(
    system.before_with_options(another_system, (
        IgnoreDeferred,
        AnyOtherOption {
            key: value
        }
    ))
);

schedule.add_systems(
    system.before_with_options(another_system, ())
);
```
2025-02-05 23:14:05 +00:00
Rob Grindeland
0335f34561
Add missing return in default Relationship::on_insert impl (#17675)
# Objective

There was a bug in the default `Relationship::on_insert` implementation
that caused it to not properly handle entities targeting themselves in
relationships. The relationship component was properly removed, but it
would go on to add itself to its own target component.

## Solution

Added a missing `return` and a couple of tests
(`self_relationship_fails` failed on its second assert prior to this
PR).

## Testing

See above.
2025-02-05 21:26:16 +00:00
ElliottjPierce
1b2cf7d6cd
Isolate component registration (#17671)
# Objective

Progresses #17569. The end goal here is to synchronize component
registration. See the other PR for details for the motivation behind
that.

For this PR specifically, the objective is to decouple `Components` from
`Storages`. What components are registered etc should have nothing to do
with what Storages looks like. Storages should only care about what
entity archetypes have been spawned.

## Solution

Previously, this was used to create sparse sets for relevant components
when those components were registered. Now, we do that when the
component is inserted/spawned.

This PR proposes doing that in `BundleInfo::new`, but there may be a
better place.

## Testing

In theory, this shouldn't have changed any functionality, so no new
tests were created. I'm not aware of any examples that make heavy use of
sparse set components either.

## Migration Guide

- Remove storages from functions where it is no longer needed.
- Note that SparseSets are no longer present for all registered sparse
set components, only those that have been spawned.

---------

Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
2025-02-05 19:59:30 +00:00
Zachary Harrold
d0c0bad7b4
Split Component::register_component_hooks into individual methods (#17685)
# Objective

- Fixes #17411

## Solution

- Deprecated `Component::register_component_hooks`
- Added individual methods for each hook which return `None` if the hook
is unused.

## Testing

- CI

---

## Migration Guide

`Component::register_component_hooks` is now deprecated and will be
removed in a future release. When implementing `Component` manually,
also implement the respective hook methods on `Component`.

```rust
// Before
impl Component for Foo {
    // snip
    fn register_component_hooks(hooks: &mut ComponentHooks) {
            hooks.on_add(foo_on_add);
    }
}

// After
impl Component for Foo {
    // snip
    fn on_add() -> Option<ComponentHook> {
            Some(foo_on_add)
    }
}
```

## Notes

I've chosen to deprecate `Component::register_component_hooks` rather
than outright remove it to ease the migration guide. While it is in a
state of deprecation, it must be used by
`Components::register_component_internal` to ensure users who haven't
migrated to the new hook definition scheme aren't left behind. For users
of the new scheme, a default implementation of
`Component::register_component_hooks` is provided which forwards the new
individual hook implementations.

Personally, I think this is a cleaner API to work with, and would allow
the documentation for hooks to exist on the respective `Component`
methods (e.g., documentation for `OnAdd` can exist on
`Component::on_add`). Ideally, `Component::on_add` would be the hook
itself rather than a getter for the hook, but it is the only way to
early-out for a no-op hook, which is important for performance.

## Migration Guide

`Component::register_component_hooks` has been deprecated. If you are
manually implementing the `Component` trait and registering hooks there,
use the individual methods such as `on_add` instead for increased
clarity.
2025-02-05 19:33:05 +00:00
couyit
03af547c28
Move Item and fetch to QueryData from WorldQuery (#17679)
# Objective

Fixes #17662

## Solution

Moved `Item` and `fetch` from `WorldQuery` to `QueryData`, and adjusted
their implementations accordingly.

Currently, documentation related to `fetch` is written under
`WorldQuery`. It would be more appropriate to move it to the `QueryData`
documentation for clarity.

I am not very experienced with making contributions. If there are any
mistakes or areas for improvement, I would appreciate any suggestions
you may have.

## Migration Guide

The `WorldQuery::Item` type and `WorldQuery::fetch` method have been
moved to `QueryData`, as they were not useful for `QueryFilter` types.

---------

Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
2025-02-05 18:46:18 +00:00
Chris Russell
6f39e44c48
Introduce methods on QueryState to obtain a Query (#15858)
# Objective

Simplify and expand the API for `QueryState`.  

`QueryState` has a lot of methods that mirror those on `Query`. These
are then multiplied by variants that take `&World`, `&mut World`, and
`UnsafeWorldCell`. In addition, many of them have `_manual` variants
that take `&QueryState` and avoid calling `update_archetypes()`. Not all
of the combinations exist, however, so some operations are not possible.

## Solution

Introduce methods to get a `Query` from a `QueryState`. That will reduce
duplication between the types, and ensure that the full `Query` API is
always available for `QueryState`.

Introduce methods on `Query` that consume the query to return types with
the full `'w` lifetime. This avoids issues with borrowing where things
like `query_state.query(&world).get(entity)` don't work because they
borrow from the temporary `Query`.

Finally, implement `Copy` for read-only `Query`s. `get_inner` and
`iter_inner` currently take `&self`, so changing them to consume `self`
would be a breaking change. By making `Query: Copy`, they can consume a
copy of `self` and continue to work.

The consuming methods also let us simplify the implementation of methods
on `Query`, by doing `fn foo(&self) { self.as_readonly().foo_inner() }`
and `fn foo_mut(&mut self) { self.reborrow().foo_inner() }`. That
structure makes it more difficult to accidentally extend lifetimes,
since the safe `as_readonly()` and `reborrow()` methods shrink them
appropriately. The optimizer is able to see that they are both identity
functions and inline them, so there should be no performance cost.

Note that this change would conflict with #15848. If `QueryState` is
stored as a `Cow`, then the consuming methods cannot be implemented, and
`Copy` cannot be implemented.

## Future Work

The next step is to mark the methods on `QueryState` as `#[deprecated]`,
and move the implementations into `Query`.

## Migration Guide

`Query::to_readonly` has been renamed to `Query::as_readonly`.
2025-02-05 18:33:15 +00:00
Vic
be9b38e372
implement UniqueEntitySlice (#17589)
# Objective

Follow-up to #17549 and #16547.

A large part of `Vec`s usefulness is behind its ability to be sliced,
like sorting f.e., so we want the same to be possible for
`UniqueEntityVec`.

## Solution

Add a `UniqueEntitySlice` type. It is a wrapper around `[T]`, and itself
a DST.

Because `mem::swap` has a `Sized` bound, DSTs cannot be swapped, and we
can freely hand out mutable subslices without worrying about the
uniqueness invariant of the backing collection!
`UniqueEntityVec` and the relevant `UniqueEntityIter`s now have methods
and trait impls that return `UniqueEntitySlice`s.
`UniqueEntitySlice` itself can deref into normal slices, which means we
can avoid implementing the vast majority of immutable slice methods.

Most of the remaining methods:
- split a slice/collection in further unique subsections/slices
- reorder the slice: `sort`, `rotate_*`, `swap`
- construct/deconstruct/convert pointer-like types: `Box`, `Arc`, `Rc`,
`Cow`
- are comparison trait impls

As this PR is already larger than I'd like, we leave several things to
follow-ups:
- `UniqueEntityArray` and the related slice methods that would return it
    - denoted by "chunk", "array_*" for iterators
- Methods that return iterators with `UniqueEntitySlice` as their item 
    - `windows`, `chunks` and `split` families
- All methods that are capable of actively mutating individual elements.
While they could be offered unsafely, subslicing makes their safety
contract weird enough to warrant its own discussion.
- `fill_with`, `swap_with_slice`, `iter_mut`, `split_first/last_mut`,
`select_nth_unstable_*`

Note that `Arc`, `Rc` and `Cow` are not fundamental types, so even if
they contain `UniqueEntitySlice`, we cannot write direct trait impls for
them.
On top of that, `Cow` is not a receiver (like `self: Arc<Self>` is) so
we cannot write inherent methods for it either.
2025-02-05 18:10:56 +00:00
Alice Cecile
0ca9d6968a
Improve docs for WorldQuery (#17654)
# Objective

While working on #17649, I found the docs for `WorldQuery` and the
related traits frustratingly vague.

## Solution

Clarify them and add some more tangible advice.

Also fix a copy-pasted typo in related comments.

---------

Co-authored-by: James O'Brien <james.obrien@drafly.net>
2025-02-03 22:13:42 +00:00
Mincong Lu
29d0ef6f3a
Added try_map_unchanged. (#17653)
# Objective

Allow mapping `Mut` to another value while returning a custom error on
failure.

## Solution

Added `try_map_unchanged` to `Mut` which returns a `Result` instead of
`Option` .
2025-02-03 22:03:39 +00:00
Chris Russell
2d66099f3d
Fix access checks for DeferredWorld as SystemParam. (#17616)
# Objective

Prevent unsound uses of `DeferredWorld` as a `SystemParam`. It is
currently unsound because it does not check for existing access, and
because it incorrectly registers filtered access.

## Solution

Have `DeferredWorld` panic if a previous parameter has conflicting
access.

Have `DeferredWorld` update `archetype_component_access` so that the
multi-threaded executor sees the access.

Fix `FilteredAccessSet::read_all()` and `write_all()` to correctly add a
`FilteredAccess` with no filter so that `Query` is able to detect the
conflicts.

Remove redundant `read_all()` call, since `write_all()` already declares
read access.

Remove unnecessary `set_has_deferred()` call, since `<DeferredWorld as
SystemParam>::apply_deferred()` does nothing. Previously we were
inserting unnecessary `apply_deferred` systems in the schedule.

## Testing

Added unit tests for systems where `DeferredWorld` conflicts with a
`Query` in the same system.
2025-02-03 21:58:07 +00:00
Joseph
721bb91987
Add basic debug checks for read-only UnsafeWorldCell (#17393)
# Objective

The method `World::as_unsafe_world_cell_readonly` is used to create an
`UnsafeWorldCell` which is only allowed to access world data immutably.
This can be tricky to use, as the data that an `UnsafeWorldCell` is
allowed to access exists only in documentation (you could think of it as
a "doc-time abstraction" rather than a "compile-time" abstraction). It's
quite easy to forget where a particular instance came from and attempt
to use it for mutable access, leading to instant, silent undefined
behavior.

## Solution

Add a debug-mode only flag to `UnsafeWorldCell` which tracks whether or
not the instance can be used to access world data mutably. This should
catch basic improper usages of `as_unsafe_world_cell_readonly`.

## Future work

There are a few ways that you can bypass the runtime checks introduced
by this PR:

* Any world accesses done via `UnsafeWorldCell::storages` are completely
invisible to these runtime checks. Unfortunately, `storages` constitutes
most of the world accesses used in the engine itself, so this PR will
mostly benefit downstream users of bevy.
* It's possible to call `get_resource_by_id`, and then convert the
returned `Ptr` to a `PtrMut` by calling `assert_unique`. In the future
we'll probably want to add a debug-mode only flag to `Ptr` which tracks
whether or not it can be upgraded to a `PtrMut`. I didn't include this
change in this PR as those types are currently defined using macros
which makes it a bit tricky to modify their definitions.
* Any data accesses done through a mutable `UnsafeWorldCell` are
completely unchecked, meaning it's possible to unsoundly create multiple
mutable references to a single component, for example. In the future we
may want to store an `Access<>` set inside of the world's `Storages` to
add granular debug-mode runtime checks.

That said, I'd consider this PR to be a good first step towards adding
full runtime checks to `UnsafeWorldCell`.

## Testing

Added a few tests that basic invalid mutable world access result in a
panic.

---------

Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
Co-authored-by: Alice I Cecile <alice.i.cecile@gmail.com>
2025-02-03 21:46:39 +00:00
Alice Cecile
da5064889a
Add required serde_derive feature flag to bevy_ecs (#17651)
# Objective

```
cargo test --package bevy_ecs --lib --all-features
```

fails to compile, with output like

> error[E0433]: failed to resolve: could not find `Serialize` in `serde`
>    --> crates/bevy_ecs/src/entity/index_set.rs:14:69
>     |
> 14 | #[cfg_attr(feature = "serialize", derive(serde::Deserialize,
serde::Serialize))]
> | ^^^^^^^^^ could not find `Serialize` in `serde`
>     |
> note: found an item that was configured out
> -->
/home/alice/.cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.217/src/lib.rs:343:37
>     |
> 343 | pub use serde_derive::{Deserialize, Serialize};
>     |                                     ^^^^^^^^^
> note: the item is gated behind the `serde_derive` feature
> -->
/home/alice/.cargo/registry/src/index.crates.io-6f17d22bba15001f/serde-1.0.217/src/lib.rs:341:7
>     |
> 341 | #[cfg(feature = "serde_derive")]
>     |       ^^^^^^^^^^^^^^^^^^^^^^^^


## Solution

Add the required feature flags and get bevy_ecs compiling standalone
corrctly.

## Testing

The command above now compiles succesfully. Note that several system
stepping tests are failing, and were not being tested in CI. That's a
different PR's problem though.
2025-02-03 03:19:57 +00:00
NiseVoid
62285a47ba
Add simple Disabled marker (#17514)
# Objective

We have default query filters now, but there is no first-party marker
for entity disabling yet
Fixes #17458

## Solution

Add the marker, cool recursive features and/or potential hook changes
should be follow up work

## Testing

Added a unit test to check that the new marker is enabled by default
2025-02-02 21:42:25 +00:00
Periwink
75e8e8c0f6
Expose ObserverDescriptor fields (#17623)
# Objective

Expose accessor functions to the `ObserverDescriptor`, so that users can
use the `Observer` component to inspect what the observer is watching.
This would be useful for me, I don't think there's any reason to hide
these.
2025-02-02 20:10:37 +00:00
Joona Aalto
9165fb020a
Implement Serialize/Deserialize for entity collections (#17620)
# Objective

Follow-up to #17615.

Bevy's entity collection types like `EntityHashSet` no longer implement
serde's `Serialize` and `Deserialize` after becoming newtypes instead of
type aliases in #16912. This broke some types that support serde for me
in Avian.

I also missed creating const constructors for `EntityIndexMap` and
`EntityIndexSet` in #17615. Oops!

## Solution

Implement `Serialize` and `Deserialize` for Bevy's entity collection
types, and add const constructors for `EntityIndexMap` and
`EntityIndexSet`.

I didn't implement `ReflectSerialize` or `ReflectDeserialize` here,
because I had some trouble fixing the resulting errors, and they were
not implemented previously either.
2025-02-02 15:42:36 +00:00
ElliottjPierce
361397fcac
Add a test for direct recursion in required components. (#17626)
I realized there wasn't a test for this yet and figured it would be
trivial to add. Why not? Unless there was a test for this, and I just
missed it?

I appreciate the unique error message it gives and wanted to make sure
it doesn't get broken at some point. Or worse, endlessly recurse.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-02-02 06:47:10 +00:00
Joona Aalto
59697f9ccc
Make EntityHashMap::new and EntityHashSet::new const (#17615)
# Objective

#16912 turned `EntityHashMap` and `EntityHashSet` into proper newtypes
instead of type aliases. However, this removed the ability to create
these collections in const contexts; previously, you could use
`EntityHashSet::with_hasher(EntityHash)`, but it doesn't exist anymore.

## Solution

Make `EntityHashMap::new` and `EntityHashSet::new` const methods.
2025-01-30 17:40:06 +00:00
Chris Russell
7d68ac029e
Use the provided caller instead of Location::caller() in despawn_with_caller() (#17598)
# Objective

Pass the correct location to triggers when despawning entities.
`EntityWorldMut::despawn_with_caller()` currently passes
`Location::caller()` to some triggers instead of the `caller` parameter
it was passed. As `despawn_with_caller()` is not `#[track_caller]`, this
means the location will always be reported as `despawn_with_caller()`
itself.

## Solution

Pass `caller` instead of `Location::caller()`.
2025-01-30 04:50:17 +00:00
Jean Mertz
b58eda01e2
feat(ecs): add EntityEntryCommands::entity() method chaining (#17580)
This allows you to continue chaining method calls after calling
`EntityCommands::entry`:

```rust
commands
    .entity(player.entity)
    .entry::<Level>()
    // Modify the component if it exists
    .and_modify(|mut lvl| lvl.0 += 1)
    // Otherwise insert a default value
    .or_insert(Level(0))
    // Return the EntityCommands for the entity
    .entity()
    // And continue chaining method calls
    .insert(Name::new("Player"));
```

---------

Signed-off-by: Jean Mertz <git@jeanmertz.com>
2025-01-29 17:36:02 +00:00
Vic
b039bf6768
implement UniqueEntityVec (#17549)
# Objective

In #16547, we added `EntitySet`s/`EntitySetIterator`s. We can know
whenever an iterator only contains unique entities, however we do not
yet have the ability to collect and reuse these without either the
unsafe `UniqueEntityIter::from_iterator_unchecked`, or the expensive
`HashSet::from_iter`.
An important piece for being able to do this is a `Vec` that maintains
the uniqueness property, can be collected into, and is itself
`EntitySet`.

A lot of entity collections are already intended to be "unique", but
have no way of expressing that when stored, other than using an
aforementioned `HashSet`. Such a type helps by limiting or even removing
the need for unsafe on the user side when not using a validated `Set`
type, and makes it easier to interface with other infrastructure like
f.e. `RelationshipSourceCollection`s.

## Solution

We implement `UniqueEntityVec`. 

This is a wrapper around `Vec`, that only ever contains unique elements.
It mirrors the API of `Vec`, however restricts any mutation as to not
violate the uniqueness guarantee. Meaning:
- Any inherent method which can introduce new elements or mutate
existing ones is now unsafe, f.e.: `insert`, `retain_mut`
- Methods that are impossible to use safely are omitted, f.e.: `fill`,
`extend_from_within`

A handful of the unsafe methods can do element-wise mutation
(`retain_mut`, `dedup_by`), which can be an unwind safety hazard were
the element-wise operation to panic. For those methods, we require that
each individual execution of the operation upholds uniqueness, not just
the entire method as a whole.

To be safe for mutable usage, slicing and the associated slice methods
require a matching `UniqueEntitySlice` type , which we leave for a
follow-up PR.

Because this type will deref into the `UniqueEntitySlice` type, we also
offer the immutable `Vec` methods on this type (which only amount to a
handful). "as inner" functionality is covered by additional
`as_vec`/`as_mut_vec` methods + `AsRef`/`Borrow` trait impls.
Like `UniqueEntityIter::from_iterator_unchecked`, this type has a
`from_vec_unchecked` method as well.

The canonical way to safely obtain this type however is via
`EntitySetIterator::collect_set` or
`UniqueEntityVec::from_entity_set_iter`. Like mentioned in #17513, these
are named suboptimally until supertrait item shadowing arrives, since a
normal `collect` will still run equality checks.
2025-01-28 06:00:59 +00:00
berry
95174f3c6e
Fix docs mistake in bevy_ecs::world (#17336)
# Objective

- Correct a mistake in the rustdoc for bevy_ecs::world::World.

## Solution

- The rustdoc wrongly stated that "Each component can have up to one
instance of each component type.". This sentence should presumably be
"Each *Entity* can have up to one instance of each component type.".
Applying this change makes the prior sentence "Each [`Entity`] has a set
of components." redundant.

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>
2025-01-28 05:20:31 +00:00
Chris Russell
514a35c656
Share implementation of sort methods. (#16203)
# Objective

The various `Query::sort()` methods have a lot of duplicated code
between them, including some unsafe code. Reduce the duplication to make
the code easier to read and maintain.

## Solution

Extract the duplicated code to a private method, and pass in the sorting
strategy as a closure.

## Testing

I used `cargo-show-asm` to verify that the closures were inlined, but I
didn't run anything through a profiler. The `sort()` method itself even
had identical assembly before and after this change, although the others
did not.
2025-01-28 04:57:54 +00:00
Tim Overbeek
eb04f8a476
Simplify derive_from_world (#17534)
# Objective

simplify existing implementation

---------

Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2025-01-26 22:25:29 +00:00
Vic
39a1e2b488
implement EntityIndexMap/Set (#17449)
# Objective

We do not have `EntityIndexMap`/`EntityIndexSet`.

Usual `HashMap`s/`HashSet`s do not guarantee any order, which can be
awkward for some use cases.
The `indexmap` versions remember insertion order, which then also
becomes their iteration order.
They can be thought of as a `HashTable` + `Vec`, which means fast
iteration and removal, indexing by index (not just key), and slicing!
Performance should otherwise be comparable.

## Solution

Because `indexmap` is structured to mirror `hashbrown`, it suffers the
same issue of not having the `Hasher` generic on their iterators. #16912
solved this issue for `EntityHashMap`/`EntityHashSet` with a wrapper
around the hashbrown version, so this PR does the same.

Hopefully these wrappers can be removed again in the future by having
`hashbrown`/`indexmap` adopt that generic in their iterators themselves!
2025-01-24 08:09:34 +00:00
Richard Jones
e20ac69cb3
Clarify docs for OnAdd, OnInsert, OnReplace, OnRemove triggers (#17512)
# Objective

- Trouble remembering the difference between `OnAdd` and `OnInsert` for
triggers. Would like a better doc for those triggers so it appears in my
editor tooltip.

## Solution

- Clarify docs for OnAdd, OnInsert, OnRemove, OnReplace. Based on
comments in the
[component_hook.rs](https://github.com/bevyengine/bevy/blob/main/examples/ecs/component_hooks.rs#L73)
example.


## Testing

- None, small doc fix.
2025-01-24 05:40:58 +00:00
Vic
94a238b0ef
implement FromEntitySetIterator (#17513)
# Objective

Some collections are more efficient to construct when we know that every
element is unique in advance.
We have `EntitySetIterator`s from #16547, but currently no API to safely
make use of them this way.

## Solution

Add `FromEntitySetIterator` as a subtrait to `FromIterator`, and
implement it for the `EntityHashSet`/`hashbrown::HashSet` types.
To match the normal `FromIterator`, we also add a
`EntitySetIterator::collect_set` method.
It'd be better if these methods could shadow `from_iter` and `collect`
completely, but https://github.com/rust-lang/rust/issues/89151 is needed
for that.

While currently only `HashSet`s implement this trait, future
`UniqueEntityVec`/`UniqueEntitySlice` functionality comes with more
implementors.

Because `HashMap`s are collected from tuples instead of singular types,
implementing this same optimization for them is more complex, and has to
be done separately.

## Showcase

This is basically a free speedup for collecting `EntityHashSet`s!

```rust
pub fn collect_milk_dippers(dippers: Query<Entity, (With<Milk>, With<Cookies>)>) {
    dippers.iter().collect_set::<EntityHashSet>();
    // or
    EntityHashSet::from_entity_set_iter(dippers);
}

---------

Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
2025-01-24 05:39:35 +00:00
Zachary Harrold
9bc0ae33c3
Move hashbrown and foldhash out of bevy_utils (#17460)
# Objective

- Contributes to #16877

## Solution

- Moved `hashbrown`, `foldhash`, and related types out of `bevy_utils`
and into `bevy_platform_support`
- Refactored the above to match the layout of these types in `std`.
- Updated crates as required.

## Testing

- CI

---

## Migration Guide

- The following items were moved out of `bevy_utils` and into
`bevy_platform_support::hash`:
  - `FixedState`
  - `DefaultHasher`
  - `RandomState`
  - `FixedHasher`
  - `Hashed`
  - `PassHash`
  - `PassHasher`
  - `NoOpHash`
- The following items were moved out of `bevy_utils` and into
`bevy_platform_support::collections`:
  - `HashMap`
  - `HashSet`
- `bevy_utils::hashbrown` has been removed. Instead, import from
`bevy_platform_support::collections` _or_ take a dependency on
`hashbrown` directly.
- `bevy_utils::Entry` has been removed. Instead, import from
`bevy_platform_support::collections::hash_map` or
`bevy_platform_support::collections::hash_set` as appropriate.
- All of the above equally apply to `bevy::utils` and
`bevy::platform_support`.

## Notes

- I left `PreHashMap`, `PreHashMapExt`, and `TypeIdMap` in `bevy_utils`
as they might be candidates for micro-crating. They can always be moved
into `bevy_platform_support` at a later date if desired.
2025-01-23 16:46:08 +00:00
Zachary Harrold
04990fcd27
Move spin to bevy_platform_support out of other crates (#17470)
# Objective

- Contributes to #16877

## Solution

- Expanded `bevy_platform_support::sync` module to provide
API-compatible replacements for `std` items such as `RwLock`, `Mutex`,
and `OnceLock`.
- Removed `spin` from all crates except `bevy_platform_support`.

## Testing

- CI

---

## Notes

- The sync primitives, while verbose, entirely rely on `spin` for their
implementation requiring no `unsafe` and not changing the status-quo on
_how_ locks actually work within Bevy. This is just a refactoring to
consolidate the "hacks" and workarounds required to get a consistent
experience when either using `std::sync` or `spin`.
- I have opted to rely on `std::sync` for `std` compatible locks,
maintaining the status quo. However, now that we have these locks
factored out into the own module, it would be trivial to investigate
alternate locking backends, such as `parking_lot`.
- API for these locking types is entirely based on `std`. I have
implemented methods and types which aren't currently in use within Bevy
(e.g., `LazyLock` and `Once`) for the sake of completeness. As the
standard library is highly stable, I don't expect the Bevy and `std`
implementations to drift apart much if at all.

---------

Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
2025-01-23 05:27:02 +00:00
Tim Overbeek
da57dfb62f
DeriveWorld for enums (#17496)
# Objective

Fixes #17457 

## Solution

#[derive(FromWorld)] now works with enums by specifying which variant
should be used.

## Showcase

```rust
#[Derive(FromWorld)]
enum Game {
    #[from_world]
    Playing, 
    Stopped
}
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
2025-01-23 04:06:00 +00:00
Zachary Harrold
41e79ae826
Refactored ComponentHook Parameters into HookContext (#17503)
# Objective

- Make the function signature for `ComponentHook` less verbose

## Solution

- Refactored `Entity`, `ComponentId`, and `Option<&Location>` into a new
`HookContext` struct.

## Testing

- CI

---

## Migration Guide

Update the function signatures for your component hooks to only take 2
arguments, `world` and `context`. Note that because `HookContext` is
plain data with all members public, you can use de-structuring to
simplify migration.

```rust
// Before
fn my_hook(
    mut world: DeferredWorld,
    entity: Entity,
    component_id: ComponentId,
) { ... }

// After
fn my_hook(
    mut world: DeferredWorld,
    HookContext { entity, component_id, caller }: HookContext,
) { ... }
``` 

Likewise, if you were discarding certain parameters, you can use `..` in
the de-structuring:

```rust
// Before
fn my_hook(
    mut world: DeferredWorld,
    entity: Entity,
    _: ComponentId,
) { ... }

// After
fn my_hook(
    mut world: DeferredWorld,
    HookContext { entity, .. }: HookContext,
) { ... }
```
2025-01-23 02:45:24 +00:00
SpecificProtagonist
f32a6fb205
Track callsite for observers & hooks (#15607)
# Objective

Fixes #14708

Also fixes some commands not updating tracked location.


## Solution

`ObserverTrigger` has a new `caller` field with the
`track_change_detection` feature;
hooks take an additional caller parameter (which is `Some(…)` or `None`
depending on the feature).

## Testing

See the new tests in `src/observer/mod.rs`

---

## Showcase

Observers now know from where they were triggered (if
`track_change_detection` is enabled):
```rust
world.observe(move |trigger: Trigger<OnAdd, Foo>| {
    println!("Added Foo from {}", trigger.caller());
});
```

## Migration

- hooks now take an additional `Option<&'static Location>` argument

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-01-22 20:02:39 +00:00
Luc
93e5e6cb95
fix double comment characters (#17484)
# Objective
- Improve docs by removing duplicate comment characters
- Fixes #17483

## Solution
- Replaced `/// ///` with `///`
2025-01-21 23:24:05 +00:00
JaySpruce
fe24652cc0
Change World::try_despawn and World::try_insert_batch to return Result (#17376)
## Objective

Most `try` methods on `World` return a `Result`, but `try_despawn` and
`try_insert_batch` don't. Since Bevy's error handling is advancing,
these should be brought in line.

## Solution

- Added `TryDespawnError` and `TryInsertBatchError`.
- `try_despawn`, `try_insert_batch`, and `try_insert_batch_if_new` now
return their respective errors.
- Fixed slightly incorrect behavior in `try_insert_batch_with_caller`.
- The method was always meant to continue with the rest of the batch if
an entity was missing, but that only worked after the first entity; if
the first entity was missing, the method would exit early. This has been
resolved.

## Migration Guide
- `World::try_despawn` now returns a `Result` rather than a `bool`.
- `World::try_insert_batch` and `World::try_insert_batch_if_new` now
return a `Result` where they previously returned nothing.
2025-01-21 23:21:32 +00:00
Alice Cecile
44ad3bf62b
Move Resource trait to its own file (#17469)
# Objective

`bevy_ecs`'s `system` module is something of a grab bag, and *very*
large. This is particularly true for the `system_param` module, which is
more than 2k lines long!

While it could be defensible to put `Res` and `ResMut` there (lol no
they're in change_detection.rs, obviously), it doesn't make any sense to
put the `Resource` trait there. This is confusing to navigate (and
painful to work on and review).

## Solution

- Create a root level `bevy_ecs/resource.rs` module to mirror
`bevy_ecs/component.rs`
- move the `Resource` trait to that module
- move the `Resource` derive macro to that module as well (Rust really
likes when you pun on the names of the derive macro and trait and put
them in the same path)
- fix all of the imports

## Notes to reviewers

- We could probably move more stuff into here, but I wanted to keep this
PR as small as possible given the absurd level of import changes.
- This PR is ground work for my upcoming attempts to store resource data
on components (resources-as-entities). Splitting this code out will make
the work and review a bit easier, and is the sort of overdue refactor
that's good to do as part of more meaningful work.

## Testing

cargo build works!

## Migration Guide

`bevy_ecs::system::Resource` has been moved to
`bevy_ecs::resource::Resource`.
2025-01-21 19:47:08 +00:00
Alice Cecile
85eceb022d
Add insert and remove recursive methods on EntityWorldMut and EntityCommands (#17463)
# Objective

While being able to quickly add / remove components down a tree is
broadly useful (material changing!), it's particularly necessary when
combined with the newly added #13120.

## Solution

Write four methods: covering both adding and removal on both
`EntityWorldMut` and `EntityCommands`.

These methods are generic over the `RelationshipTarget`, thanks to the
freshly merged relations 🎉

## Testing

I've added a simple unit test for these methods.

---------

Co-authored-by: Zachary Harrold <zac@harrold.com.au>
2025-01-21 02:57:57 +00:00
AlephCubed
42b928b90e
Added helper methods to Bundles. (#17464)
Added `len`, `is_empty`, and `iter` methods to `Bundles`.

Separated out from #17331.

---------

Co-authored-by: shuo <shuoli84@gmail.com>
2025-01-21 02:19:02 +00:00
Alice Cecile
b34833f00c
Add an example teaching users about custom relationships (#17443)
# Objective

After #17398, Bevy now has relations! We don't teach users how to make /
work with these in the examples yet though, but we definitely should.

## Solution

- Add a simple abstract example that goes over defining, spawning,
traversing and removing a custom relations.
- ~~Add `Relationship` and `RelationshipTarget` to the prelude: the
trait methods are really helpful here.~~
- this causes subtle ambiguities with method names and weird compiler
errors. Not doing it here!
- Clean up related documentation that I referenced when writing this
example.

## Testing

`cargo run --example relationships`

## Notes to reviewers

1. Yes, I know that the cycle detection code could be more efficient. I
decided to reduce the caching to avoid distracting from the broader
point of "here's how you traverse relationships".
2. Instead of using an `App`, I've decide to use
`World::run_system_once` + system functions defined inside of `main` to
do something closer to literate programming.

---------

Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
2025-01-20 23:17:38 +00:00
Carter Anderson
ba5e71f53d
Parent -> ChildOf (#17427)
Fixes #17412

## Objective

`Parent` uses the "has a X" naming convention. There is increasing
sentiment that we should use the "is a X" naming convention for
relationships (following #17398). This leaves `Children` as-is because
there is prevailing sentiment that `Children` is clearer than `ParentOf`
in many cases (especially when treating it like a collection).

This renames `Parent` to `ChildOf`.

This is just the implementation PR. To discuss the path forward, do so
in #17412.

## Migration Guide

- The `Parent` component has been renamed to `ChildOf`.
2025-01-20 22:13:29 +00:00
NiseVoid
de5486725d
Add DefaultQueryFilters (#13120)
# Objective

Some usecases in the ecosystems are blocked by the inability to stop
bevy internals and third party plugins from touching their entities.
However the specifics of a general purpose entity disabling system are
controversial and further complicated by hierarchies. We can partially
unblock these usecases with an opt-in approach: default query filters.

## Solution

- Introduce DefaultQueryFilters, these filters are automatically applied
to queries that don't otherwise mention the filtered component.
- End users and third party plugins can register default filters and are
responsible for handling entities they have hidden this way.
- Extra features can be left for after user feedback
- The default value could later include official ways to hide entities

---

## Changelog

- Add DefaultQueryFilters
2025-01-20 21:57:39 +00:00
SpecificProtagonist
a7051a4815
Diagnostics for label traits (#17441)
# Objective

Diagnostics for labels don't suggest how to best implement them.
```
error[E0277]: the trait bound `Label: ScheduleLabel` is not satisfied
   --> src/main.rs:15:35
    |
15  |     let mut sched = Schedule::new(Label);
    |                     ------------- ^^^^^ the trait `ScheduleLabel` is not implemented for `Label`
    |                     |
    |                     required by a bound introduced by this call
    |
    = help: the trait `ScheduleLabel` is implemented for `Interned<(dyn ScheduleLabel + 'static)>`
note: required by a bound in `bevy_ecs::schedule::Schedule::new`
   --> /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/schedule.rs:297:28
    |
297 |     pub fn new(label: impl ScheduleLabel) -> Self {
    |                            ^^^^^^^^^^^^^ required by this bound in `Schedule::new`
```

## Solution

`diagnostics::on_unimplemented` and `diagnostics::do_not_recommend`

## Showcase

New error message:
```
error[E0277]: the trait bound `Label: ScheduleLabel` is not satisfied
   --> src/main.rs:15:35
    |
15  |     let mut sched = Schedule::new(Label);
    |                     ------------- ^^^^^ the trait `ScheduleLabel` is not implemented for `Label`
    |                     |
    |                     required by a bound introduced by this call
    |
    = note: consider annotating `Label` with `#[derive(ScheduleLabel)]`
note: required by a bound in `bevy_ecs::schedule::Schedule::new`
   --> /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/schedule.rs:297:28
    |
297 |     pub fn new(label: impl ScheduleLabel) -> Self {
    |                            ^^^^^^^^^^^^^ required by this bound in `Schedule::new`
```
2025-01-20 21:51:26 +00:00
Younes
ebbd961739
docs: enhance documentation in query.rs to clarify borrowing rules (#17370)
docs: enhance documentation in `query.rs` to clarify borrowing rules.

Please, let me know if you don't agree with the wording.. There is
always room for improvement.

Tested locally and it looks like this:


![image](https://github.com/user-attachments/assets/1283fcac-c5f7-426f-844f-fc2a12ce2b42)

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-01-20 21:31:20 +00:00
Vic
59657ed1e2
remove unsound DerefMut impls from EntityHashMap/EntityHashSet (#17450)
# Objective

Noticed while doing #17449, I had left these `DerefMut` impls in.
Obtaining mutable references to those inner iterator types allows for
`mem::swap`, which can be used to swap an incorrectly behaving instance
into the wrappers.

## Solution

Remove them!
2025-01-20 21:28:28 +00:00
Alice Cecile
5a9bc28502
Support non-Vec data structures in relations (#17447)
# Objective

The existing `RelationshipSourceCollection` uses `Vec` as the only
possible backing for our relationships. While a reasonable choice,
benchmarking use cases might reveal that a different data type is better
or faster.

For example:

- Not all relationships require a stable ordering between the
relationship sources (i.e. children). In cases where we a) have many
such relations and b) don't care about the ordering between them, a hash
set is likely a better datastructure than a `Vec`.
- The number of children-like entities may be small on average, and a
`smallvec` may be faster

## Solution

- Implement `RelationshipSourceCollection` for `EntityHashSet`, our
custom entity-optimized `HashSet`.
-~~Implement `DoubleEndedIterator` for `EntityHashSet` to make things
compile.~~
   -  This implementation was cursed and very surprising.
- Instead, by moving the iterator type on `RelationshipSourceCollection`
from an erased RPTIT to an explicit associated type we can add a trait
bound on the offending methods!
- Implement `RelationshipSourceCollection` for `SmallVec`

## Testing

I've added a pair of new tests to make sure this pattern compiles
successfully in practice!

## Migration Guide

`EntityHashSet` and `EntityHashMap` are no longer re-exported in
`bevy_ecs::entity` directly. If you were not using `bevy_ecs` / `bevy`'s
`prelude`, you can access them through their now-public modules,
`hash_set` and `hash_map` instead.

## Notes to reviewers

The `EntityHashSet::Iter` type needs to be public for this impl to be
allowed. I initially renamed it to something that wasn't ambiguous and
re-exported it, but as @Victoronz pointed out, that was somewhat
unidiomatic.

In
1a8564898f,
I instead made the `entity_hash_set` public (and its `entity_hash_set`)
sister public, and removed the re-export. I prefer this design (give me
module docs please), but it leads to a lot of churn in this PR.

Let me know which you'd prefer, and if you'd like me to split that
change out into its own micro PR.
2025-01-20 21:26:08 +00:00
Emerson Coskey
a99674ab86
FromWorld derive macro (#17352)
simple derive macro for `FromWorld`. Going to be needed for composable
pipeline specializers but probably a nice thing to have regardless

## Testing

simple manual testing, nothing seemed to blow up. I'm no proc macro pro
though, so there's a chance I've mishandled spans somewhere or
something.
2025-01-20 20:51:30 +00:00
Zachary Harrold
a64446b77e
Create bevy_platform_support Crate (#17250)
# Objective

- Contributes to #16877

## Solution

- Initial creation of `bevy_platform_support` crate.
- Moved `bevy_utils::Instant` into new `bevy_platform_support` crate.
- Moved `portable-atomic`, `portable-atomic-util`, and
`critical-section` into new `bevy_platform_support` crate.

## Testing

- CI

---

## Showcase

Instead of needing code like this to import an `Arc`:

```rust
#[cfg(feature = "portable-atomic")]
use portable_atomic_util::Arc;

#[cfg(not(feature = "portable-atomic"))]
use alloc::sync::Arc;
```

We can now use:

```rust
use bevy_platform_support::sync::Arc;
```

This applies to many other types, but the goal is overall the same:
allowing crates to use `std`-like types without the boilerplate of
conditional compilation and platform-dependencies.

## Migration Guide

- Replace imports of `bevy_utils::Instant` with
`bevy_platform_support::time::Instant`
- Replace imports of `bevy::utils::Instant` with
`bevy::platform_support::time::Instant`

## Notes

- `bevy_platform_support` hasn't been reserved on `crates.io`
- ~~`bevy_platform_support` is not re-exported from `bevy` at this time.
It may be worthwhile exporting this crate, but I am unsure of a
reasonable name to export it under (`platform_support` may be a bit
wordy for user-facing).~~
- I've included an implementation of `Instant` which is suitable for
`no_std` platforms that are not Wasm for the sake of eliminating feature
gates around its use. It may be a controversial inclusion, so I'm happy
to remove it if required.
- There are many other items (`spin`, `bevy_utils::Sync(Unsafe)Cell`,
etc.) which should be added to this crate. I have kept the initial scope
small to demonstrate utility without making this too unwieldy.

---------

Co-authored-by: TimJentzsch <TimJentzsch@users.noreply.github.com>
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2025-01-20 20:45:30 +00:00
Carter Anderson
21f1e3045c
Relationships (non-fragmenting, one-to-many) (#17398)
This adds support for one-to-many non-fragmenting relationships (with
planned paths for fragmenting and non-fragmenting many-to-many
relationships). "Non-fragmenting" means that entities with the same
relationship type, but different relationship targets, are not forced
into separate tables (which would cause "table fragmentation").

Functionally, this fills a similar niche as the current Parent/Children
system. The biggest differences are:

1. Relationships have simpler internals and significantly improved
performance and UX. Commands and specialized APIs are no longer
necessary to keep everything in sync. Just spawn entities with the
relationship components you want and everything "just works".
2. Relationships are generalized. Bevy can provide additional built in
relationships, and users can define their own.

**REQUEST TO REVIEWERS**: _please don't leave top level comments and
instead comment on specific lines of code. That way we can take
advantage of threaded discussions. Also dont leave comments simply
pointing out CI failures as I can read those just fine._

## Built on top of what we have

Relationships are implemented on top of the Bevy ECS features we already
have: components, immutability, and hooks. This makes them immediately
compatible with all of our existing (and future) APIs for querying,
spawning, removing, scenes, reflection, etc. The fewer specialized APIs
we need to build, maintain, and teach, the better.

## Why focus on one-to-many non-fragmenting first?

1. This allows us to improve Parent/Children relationships immediately,
in a way that is reasonably uncontroversial. Switching our hierarchy to
fragmenting relationships would have significant performance
implications. ~~Flecs is heavily considering a switch to non-fragmenting
relations after careful considerations of the performance tradeoffs.~~
_(Correction from @SanderMertens: Flecs is implementing non-fragmenting
storage specialized for asset hierarchies, where asset hierarchies are
many instances of small trees that have a well defined structure)_
2. Adding generalized one-to-many relationships is currently a priority
for the [Next Generation Scene / UI
effort](https://github.com/bevyengine/bevy/discussions/14437).
Specifically, we're interested in building reactions and observers on
top.

## The changes

This PR does the following:

1. Adds a generic one-to-many Relationship system
3. Ports the existing Parent/Children system to Relationships, which now
lives in `bevy_ecs::hierarchy`. The old `bevy_hierarchy` crate has been
removed.
4. Adds on_despawn component hooks
5. Relationships can opt-in to "despawn descendants" behavior, meaning
that the entire relationship hierarchy is despawned when
`entity.despawn()` is called. The built in Parent/Children hierarchies
enable this behavior, and `entity.despawn_recursive()` has been removed.
6. `world.spawn` now applies commands after spawning. This ensures that
relationship bookkeeping happens immediately and removes the need to
manually flush. This is in line with the equivalent behaviors recently
added to the other APIs (ex: insert).
7. Removes the ValidParentCheckPlugin (system-driven / poll based) in
favor of a `validate_parent_has_component` hook.

## Using Relationships

The `Relationship` trait looks like this:

```rust
pub trait Relationship: Component + Sized {
    type RelationshipSources: RelationshipSources<Relationship = Self>;
    fn get(&self) -> Entity;
    fn from(entity: Entity) -> Self;
}
```

A relationship is a component that:

1. Is a simple wrapper over a "target" Entity.
2. Has a corresponding `RelationshipSources` component, which is a
simple wrapper over a collection of entities. Every "target entity"
targeted by a "source entity" with a `Relationship` has a
`RelationshipSources` component, which contains every "source entity"
that targets it.

For example, the `Parent` component (as it currently exists in Bevy) is
the `Relationship` component and the entity containing the Parent is the
"source entity". The entity _inside_ the `Parent(Entity)` component is
the "target entity". And that target entity has a `Children` component
(which implements `RelationshipSources`).

In practice, the Parent/Children relationship looks like this:

```rust
#[derive(Relationship)]
#[relationship(relationship_sources = Children)]
pub struct Parent(pub Entity);

#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent)]
pub struct Children(Vec<Entity>);
```

The Relationship and RelationshipSources derives automatically implement
Component with the relevant configuration (namely, the hooks necessary
to keep everything in sync).

The most direct way to add relationships is to spawn entities with
relationship components:

```rust
let a = world.spawn_empty().id();
let b = world.spawn(Parent(a)).id();

assert_eq!(world.entity(a).get::<Children>().unwrap(), &[b]);
```

There are also convenience APIs for spawning more than one entity with
the same relationship:

```rust
world.spawn_empty().with_related::<Children>(|s| {
    s.spawn_empty();
    s.spawn_empty();
})
```

The existing `with_children` API is now a simpler wrapper over
`with_related`. This makes this change largely non-breaking for existing
spawn patterns.

```rust
world.spawn_empty().with_children(|s| {
    s.spawn_empty();
    s.spawn_empty();
})
```

There are also other relationship APIs, such as `add_related` and
`despawn_related`.

## Automatic recursive despawn via the new on_despawn hook

`RelationshipSources` can opt-in to "despawn descendants" behavior,
which will despawn all related entities in the relationship hierarchy:

```rust
#[derive(RelationshipSources)]
#[relationship_sources(relationship = Parent, despawn_descendants)]
pub struct Children(Vec<Entity>);
```

This means that `entity.despawn_recursive()` is no longer required.
Instead, just use `entity.despawn()` and the relevant related entities
will also be despawned.

To despawn an entity _without_ despawning its parent/child descendants,
you should remove the `Children` component first, which will also remove
the related `Parent` components:

```rust
entity
    .remove::<Children>()
    .despawn()
```

This builds on the on_despawn hook introduced in this PR, which is fired
when an entity is despawned (before other hooks).

## Relationships are the source of truth

`Relationship` is the _single_ source of truth component.
`RelationshipSources` is merely a reflection of what all the
`Relationship` components say. By embracing this, we are able to
significantly improve the performance of the system as a whole. We can
rely on component lifecycles to protect us against duplicates, rather
than needing to scan at runtime to ensure entities don't already exist
(which results in quadratic runtime). A single source of truth gives us
constant-time inserts. This does mean that we cannot directly spawn
populated `Children` components (or directly add or remove entities from
those components). I personally think this is a worthwhile tradeoff,
both because it makes the performance much better _and_ because it means
theres exactly one way to do things (which is a philosophy we try to
employ for Bevy APIs).

As an aside: treating both sides of the relationship as "equivalent
source of truth relations" does enable building simple and flexible
many-to-many relationships. But this introduces an _inherent_ need to
scan (or hash) to protect against duplicates.
[`evergreen_relations`](https://github.com/EvergreenNest/evergreen_relations)
has a very nice implementation of the "symmetrical many-to-many"
approach. Unfortunately I think the performance issues inherent to that
approach make it a poor choice for Bevy's default relationship system.

## Followup Work

* Discuss renaming `Parent` to `ChildOf`. I refrained from doing that in
this PR to keep the diff reasonable, but I'm personally biased toward
this change (and using that naming pattern generally for relationships).
* [Improved spawning
ergonomics](https://github.com/bevyengine/bevy/discussions/16920)
* Consider adding relationship observers/triggers for "relationship
targets" whenever a source is added or removed. This would replace the
current "hierarchy events" system, which is unused upstream but may have
existing users downstream. I think triggers are the better fit for this
than a buffered event queue, and would prefer not to add that back.
* Fragmenting relations: My current idea hinges on the introduction of
"value components" (aka: components whose type _and_ value determines
their ComponentId, via something like Hashing / PartialEq). By labeling
a Relationship component such as `ChildOf(Entity)` as a "value
component", `ChildOf(e1)` and `ChildOf(e2)` would be considered
"different components". This makes the transition between fragmenting
and non-fragmenting a single flag, and everything else continues to work
as expected.
* Many-to-many support
* Non-fragmenting: We can expand Relationship to be a list of entities
instead of a single entity. I have largely already written the code for
this.
* Fragmenting: With the "value component" impl mentioned above, we get
many-to-many support "for free", as it would allow inserting multiple
copies of a Relationship component with different target entities.

Fixes #3742 (If this PR is merged, I think we should open more targeted
followup issues for the work above, with a fresh tracking issue free of
the large amount of less-directed historical context)
Fixes #17301
Fixes #12235 
Fixes #15299
Fixes #15308 

## Migration Guide

* Replace `ChildBuilder` with `ChildSpawnerCommands`.
* Replace calls to `.set_parent(parent_id)` with
`.insert(Parent(parent_id))`.
* Replace calls to `.replace_children()` with `.remove::<Children>()`
followed by `.add_children()`. Note that you'll need to manually despawn
any children that are not carried over.
* Replace calls to `.despawn_recursive()` with `.despawn()`.
* Replace calls to `.despawn_descendants()` with
`.despawn_related::<Children>()`.
* If you have any calls to `.despawn()` which depend on the children
being preserved, you'll need to remove the `Children` component first.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-01-18 22:20:30 +00:00
Christian Hughes
14a955c5eb
Add usage notes for the IntoX family of ECS traits (#17379)
# Objective

Occasionally bevy users will want to store systems or observer systems
in a component or resource, but they first try to store `IntoSystem`
instead of `System`, which leads to some headaches having to deal with
the `M` marker type parameter. We should recommend they use the `X`
trait instead of the `IntoX` trait in that case, as well for returning
from a function.

## Solution

Add usage notes to the `IntoX` traits about using `X` instead.
2025-01-17 01:18:22 +00:00
Zachary Harrold
5cc3f4727e
Implement Clone for QueryIter over read-only data (#17391)
# Objective

- Fix issue identified on the [Discord
server](https://discord.com/channels/691052431525675048/691052431974465548/1328922812530036839)

## Solution

- Implement `Clone` for `QueryIter` using the existing
`QueryIter::remaining` method

## Testing

- CI

---

## Showcase

Users can now explicitly clone a read-only `QueryIter`:

```rust
fn combinations(query: Query<&ComponentA>) {
    let mut iter = query.iter();
    while let Some(a) = iter.next() {
        // Can now clone rather than use remaining
        for b in iter.clone() {
            // Check every combination (a, b)
        }
    }
}
```


## Notes

This doesn't add any new functionality outside the context of generic
code (e.g., `T: Iterator<...> + Clone`), it's mostly for
discoverability. Users are more likely to be familiar with
`Clone::clone` than they are with the methods on `QueryIter`.
2025-01-15 21:56:11 +00:00
Alice Cecile
237c6b207e
Remove Event: Component trait bound using a wrapper type which impls Component (#17380)
# Objective

As raised in https://github.com/bevyengine/bevy/pull/17317, the `Event:
Component` trait bound is confusing to users.

In general, a type `E` (like `AppExit`) which implements `Event` should
not:

- be stored as a component on an entity
- be a valid option for `Query<&AppExit>`
- require the storage type and other component metadata to be specified

Events are not components (even if they one day use some of the same
internal mechanisms), and this trait bound is confusing to users.

We're also automatically generating `Component` impls with our derive
macro, which should be avoided when possible to improve explicitness and
avoid conflicts with user impls.

Closes #17317, closes #17333

## Solution

- We only care that each unique event type gets a unique `ComponentId`
- dynamic events need their own tools for getting identifiers anyways
- This avoids complicating the internals of `ComponentId` generation.
- Clearly document why this cludge-y solution exists.

In the medium term, I think that either a) properly generalizing
`ComponentId` (and moving it into `bevy_reflect?) or b) using a
new-typed `Entity` as the key for events is more correct. This change is
stupid simple though, and removes the offending trait bound in a way
that doesn't introduce complex tech debt and does not risk changes to
the internals.

This change does not:

- restrict our ability to implement dynamic buffered events (the main
improvement over #17317)
- there's still a fair bit of work to do, but this is a step in the
right direction
- limit our ability to store event metadata on entities in the future
- make it harder for users to work with types that are both events and
components (just add the derive / trait bound)

## Migration Guide

The `Event` trait no longer requires the `Component` trait. If you were
relying on this behavior, change your trait bounds from `Event` to
`Event + Component`. If you also want your `Event` type to implement
`Component`, add a derive.

---------

Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
2025-01-15 18:42:47 +00:00
MichiRecRoom
26bb0b40d2
Move #![warn(clippy::allow_attributes, clippy::allow_attributes_without_reason)] to the workspace Cargo.toml (#17374)
# Objective
Fixes https://github.com/bevyengine/bevy/issues/17111

## Solution
Move `#![warn(clippy::allow_attributes,
clippy::allow_attributes_without_reason)]` to the workspace `Cargo.toml`

## Testing
Lots of CI testing, and local testing too.

---------

Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
2025-01-15 01:14:58 +00:00
Adrian Kortyczko
dcff8f3ecb
Make ObservedBy public (#17297)
# Objective
- Currently, the `ObservedBy`-component is only public within the
`bevy_ecs` crate. Sometimes it is desirable to refer to this component
in the "game-code". Two examples that come in mind:
- Clearing all components in an entity, but intending to keep the
existing observers: Making `ObservedBy` public allows us to use
`commands.entity(entity).retain::<ObservedBy>();`, which clears all
other components, but keeps `ObservedBy`, which prevents the Observers
from despawning.
- The opposite of the above, clearing all of entities' Observers:
`commands.entity(entity).remove::<ObservedBy>` will despawn all
associated Observers. Admittedly, a cleaner solution would be something
like `commands.entity(entity).clear_observers()`, but this is
sufficient.

## Solution

- Removed `(crate)` "rule" and added `ObservedBy` to the prelude-module

## Testing

- Linked `bevy_ecs` locally with another project to see if `ObservedBy`
could be referenced.
2025-01-14 21:53:42 +00:00
Jaso333
9ef1964d34
added any_match_filter common condition (#17327)
# Objective

resolves #17326.

## Solution

Simply added the suggested run condition.

## Testing

A self-explanatory run condition. Fully verified by the operation of
`QueryFilter` in a system.
2025-01-14 21:53:35 +00:00
Younes
276d6e8014
fix typo query.rs (#17366)
fix typo query.rs
2025-01-14 21:53:19 +00:00
MichiRecRoom
17c46f4add
bevy_ecs: Apply #![warn(clippy::allow_attributes, clippy::allow_attributes_without_reason)] (#17335)
# Objective
- https://github.com/bevyengine/bevy/issues/17111

## Solution
Set the `clippy::allow_attributes` and
`clippy::allow_attributes_without_reason` lints to `warn`, and bring
`bevy_ecs` in line with the new restrictions.

## Testing
This PR is a WIP; testing will happen after it's finished.
2025-01-14 21:37:41 +00:00
Younes
031bb09737
Refactor event system documentation in system_param.rs (#17364)
Just clarify the role of `ParamSet` in this code snippet
2025-01-14 19:38:25 +00:00
Alexis "spectria.limina" Horizon
4dfa87798f
Add std derives to SystemParam types (#16785)
# Objective

- Use `Clone` on `SystemParam`, when applicable, in a generic context.

## Solution

-  Add some derives

## Testing

- I ran `cargo test` once.
- I didn't even look at the output.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
2025-01-14 00:30:51 +00:00
AlephCubed
e808fbe987
Renamed members of ParamWarnPolicy to reflect new behaviour. (#17311)
- `Once` renamed to `Warn`.
- `param_warn_once()` renamed to `warn_param_missing()`.
- `never_param_warn()` renamed to `ignore_param_missing()`.

Also includes changes to the documentation of the above methods.

Fixes #17262.

## Migration Guide
- `ParamWarnPolicy::Once` has been renamed to `ParamWarnPolicy::Warn`.
- `ParamWarnPolicy::param_warn_once` has been renamed to
`ParamWarnPolicy::warn_param_missing`.
- `ParamWarnPolicy::never_param_warn` has been renamed to
`ParamWarnPolicy::ignore_param_missing`.
2025-01-12 05:40:04 +00:00
SpecificProtagonist
f5d38f30cc
Fix entity does not exist message on index reuse (#17264)
# Objective

With the `track_location` feature, the error message of trying to
acquire an entity that was despawned pointed to the wrong line if the
entity index has been reused.

## Showcase

```rust
use bevy_ecs::prelude::*;

fn main() {
    let mut world = World::new();
    let e = world.spawn_empty().id();
    world.despawn(e);
    world.flush();
    let _ = world.spawn_empty();
    world.entity(e);
}
```
Old message:
```
Entity 0v1 was despawned by src/main.rs:8:19
```
New message:
```
Entity 0v1 does not exist (its index has been reused)
```
2025-01-12 05:39:54 +00:00
Rob Parrett
b77e3ef33a
Fix a few typos (#17292)
# Objective

Stumbled upon a `from <-> form` transposition while reviewing a PR,
thought it was interesting, and went down a bit of a rabbit hole.

## Solution

Fix em
2025-01-10 22:48:30 +00:00
Carter Anderson
4bca7f1b6d
Improved Command Errors (#17215)
# Objective

Rework / build on #17043 to simplify the implementation. #17043 should
be merged first, and the diff from this PR will get much nicer after it
is merged (this PR is net negative LOC).

## Solution

1. Command and EntityCommand have been vastly simplified. No more marker
components. Just one function.
2. Command and EntityCommand are now generic on the return type. This
enables result-less commands to exist, and allows us to statically
distinguish between fallible and infallible commands, which allows us to
skip the "error handling overhead" for cases that don't need it.
3. There are now only two command queue variants: `queue` and
`queue_fallible`. `queue` accepts commands with no return type.
`queue_fallible` accepts commands that return a Result (specifically,
one that returns an error that can convert to
`bevy_ecs::result::Error`).
4. I've added the concept of the "default error handler", which is used
by `queue_fallible`. This is a simple direct call to the `panic()` error
handler by default. Users that want to override this can enable the
`configurable_error_handler` cargo feature, then initialize the
GLOBAL_ERROR_HANDLER value on startup. This is behind a flag because
there might be minor overhead with `OnceLock` and I'm guessing this will
be a niche feature. We can also do perf testing with OnceLock if someone
really wants it to be used unconditionally, but I don't personally feel
the need to do that.
5. I removed the "temporary error handler" on Commands (and all code
associated with it). It added more branching, made Commands bigger /
more expensive to initialize (note that we construct it at high
frequencies / treat it like a pointer type), made the code harder to
follow, and introduced a bunch of additional functions. We instead rely
on the new default error handler used in `queue_fallible` for most
things. In the event that a custom handler is required,
`handle_error_with` can be used.
6. EntityCommand now _only_ supports functions that take
`EntityWorldMut` (and all existing entity commands have been ported).
Removing the marker component from EntityCommand hinged on this change,
but I strongly believe this is for the best anyway, as this sets the
stage for more efficient batched entity commands.
7. I added `EntityWorldMut::resource` and the other variants for more
ergonomic resource access on `EntityWorldMut` (removes the need for
entity.world_scope, which also incurs entity-lookup overhead).

## Open Questions

1. I believe we could merge `queue` and `queue_fallible` into a single
`queue` which accepts both fallible and infallible commands (via the
introduction of a `QueueCommand` trait). Is this desirable?
2025-01-10 04:15:50 +00:00
mgi388
b20e23dd41
Add compile-time dyn compatible checks for DynEq, DynHash (#17254)
# Objective

- Shrink `bevy_utils` more.
- Refs #11478

## Solution

- Removes `assert_object_safe` from `bevy_utils` by using a compile time
check instead.

## Testing

- CI.

---

## Migration Guide

`assert_object_safe` is no longer exported by `bevy_utils`. Instead, you
can write a compile time check that your trait is "dyn compatible":

```rust
/// Assert MyTrait is dyn compatible
const _: Option<Box<dyn MyTrait>> = None;
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2025-01-09 07:30:54 +00:00
MichiRecRoom
3742e621ef
Allow clippy::too_many_arguments to lint without warnings (#17249)
# Objective
Many instances of `clippy::too_many_arguments` linting happen to be on
systems - functions which we don't call manually, and thus there's not
much reason to worry about the argument count.

## Solution
Allow `clippy::too_many_arguments` globally, and remove all lint
attributes related to it.
2025-01-09 07:26:15 +00:00
JaySpruce
ee4414159b
Add Result handling to Commands and EntityCommands (#17043)
## Objective

Fixes #2004
Fixes #3845
Fixes #7118
Fixes #10166

## Solution

- The crux of this PR is the new `Command::with_error_handling` method.
This wraps the relevant command in another command that, when applied,
will apply the original command and handle any resulting errors.
- To enable this, `Command::apply` and `EntityCommand::apply` now return
`Result`.
- `Command::with_error_handling` takes as a parameter an error handler
of the form `fn(&mut World, CommandError)`, which it passes the error
to.
- `CommandError` is an enum that can be either `NoSuchEntity(Entity)` or
`CommandFailed(Box<dyn Error>)`.

### Closures
- Closure commands can now optionally return `Result`, which will be
passed to `with_error_handling`.

### Commands
- Fallible commands can be queued with `Commands::queue_fallible` and
`Commands::queue_fallible_with`, which call `with_error_handling` before
queuing them (using `Commands::queue` will queue them without error
handling).
- `Commands::queue_fallible_with` takes an `error_handler` parameter,
which will be used by `with_error_handling` instead of a command's
default.
- The `command` submodule provides unqueued forms of built-in fallible
commands so that you can use them with `queue_fallible_with`.
- There is also an `error_handler` submodule that provides simple error
handlers for convenience.

### Entity Commands
- `EntityCommand` now automatically checks if the entity exists before
executing the command, and returns `NoSuchEntity` if it doesn't.
- Since all entity commands might need to return an error, they are
always queued with error handling.
- `EntityCommands::queue_with` takes an `error_handler` parameter, which
will be used by `with_error_handling` instead of a command's default.
- The `entity_command` submodule provides unqueued forms of built-in
entity commands so that you can use them with `queue_with`.

### Defaults
- In the future, commands should all fail according to the global error
handling setting. That doesn't exist yet though.
- For this PR, commands all fail the way they do on `main`.
- Both now and in the future, the defaults can be overridden by
`Commands::override_error_handler` (or equivalent methods on
`EntityCommands` and `EntityEntryCommands`).
- `override_error_handler` takes an error handler (`fn(&mut World,
CommandError)`) and passes it to every subsequent command queued with
`Commands::queue_fallible` or `EntityCommands::queue`.
- The `_with` variants of the queue methods will still provide an error
handler directly to the command.
- An override can be reset with `reset_error_handler`.

## Future Work

- After a universal error handling mode is added, we can change all
commands to fail that way by default.
- Once we have all commands failing the same way (which would require
either the full removal of `try` variants or just making them useless
while they're deprecated), `queue_fallible_with_default` could be
removed, since its only purpose is to enable commands having different
defaults.
2025-01-07 16:50:52 +00:00
Christian Hughes
d1e5702020
Replace unsafe blocks in World and DeferredWorld with safe equivalents (#17206)
# Objective

Reduce the number of unsafe blocks.

## Solution

Replaced 5 unsafe blocks with safe equivalents.

## Testing

Reusing current tests
2025-01-07 03:21:47 +00:00
Christian Hughes
f64f3ac997
Cleanup entity reference types (#17149)
# Objective

Cleanup `EntityRef`, `EntityMut`, and `EntityWorldMut` in preparation
for my "Scoped Entity References" PR.

## Solution

- Switched `EntityRef`/`EntityMut` from tuple structs to normal ones.
- Ensured all conversion trait impls use the same `entity` argument
name.
- Replaced some `unsafe` with delegated calls from `EntityMut` to
`EntityRef`
    - Added `EntityMut::into_readonly` to make the replacements clearer
- Replaced some `unsafe` with delegated calls from `EntityWorldMut` to
`EntityMut` and `EntityRef`
- Added `EntityWorldMut::into_readonly`, `::as_readonly`,
`::into_mutable`, `::as_mutable` to make the replacements clearer

## Testing

Reusing current tests.
2025-01-06 19:25:06 +00:00
vil'mo
b30ee2d051
Disallow requesting write resource access in Queries (#17116)
Related to https://github.com/bevyengine/bevy/pull/16843

Since `WorldQuery::Fetch` is `Clone`, it can't store mutable references
to resources, so it doesn't make sense to mutably access resources. In
that sense, it is hard to find usecases of mutably accessing resources
and to clearly define, what mutably accessing resources would mean, so
it's been decided to disallow write resource access.
Also changed documentation of safety requirements of
`WorldQuery::init_fetch` and `WorldQuery::fetch` to clearly state to the
caller, what safety invariants they need to uphold.
2025-01-06 19:04:26 +00:00
github-actions[bot]
573b980685
Bump Version after Release (#17176)
Bump version after release
This PR has been auto-generated

---------

Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
2025-01-06 00:04:44 +00:00
Zachary Harrold
a371ee3019
Remove tracing re-export from bevy_utils (#17161)
# Objective

- Contributes to #11478

## Solution

- Made `bevy_utils::tracing` `doc(hidden)`
- Re-exported `tracing` from `bevy_log` for end-users
- Added `tracing` directly to crates that need it.

## Testing

- CI

---

## Migration Guide

If you were importing `tracing` via `bevy::utils::tracing`, instead use
`bevy::log::tracing`. Note that many items within `tracing` are also
directly re-exported from `bevy::log` as well, so you may only need
`bevy::log` for the most common items (e.g., `warn!`, `trace!`, etc.).
This also applies to the `log_once!` family of macros.

## Notes

- While this doesn't reduce the line-count in `bevy_utils`, it further
decouples the internal crates from `bevy_utils`, making its eventual
removal more feasible in the future.
- I have just imported `tracing` as we do for all dependencies. However,
a workspace dependency may be more appropriate for version management.
2025-01-05 23:06:34 +00:00
Benjamin Brienen
7112d5594e
Remove all deprecated code (#16338)
# Objective

Release cycle things

## Solution

Delete items deprecated in 0.15 and migrate bevy itself.

## Testing

CI
2025-01-05 20:33:39 +00:00
JaySpruce
4fde223831
Optimize Entities::entity_does_not_exist_error_details_message, remove UnsafeWorldCell from error (#17115)
## Objective

The error `EntityFetchError::NoSuchEntity` has an `UnsafeWorldCell`
inside it, which it uses to call
`Entities::entity_does_not_exist_error_details_message` when being
printed. That method returns a `String` that, if the `track_location`
feature is enabled, contains the location of whoever despawned the
relevant entity.

I initially had to modify this error while working on #17043. The
`UnsafeWorldCell` was causing borrow problems when being returned from a
command, so I tried replacing it with the `String` that the method
returns, since that was the world cell's only purpose.

Unfortunately, `String`s are slow, and it significantly impacted
performance (on top of that PR's performance hit):
<details>
<summary>17043 benchmarks</summary>

### With `String`

![error_handling_insert_slow](https://github.com/user-attachments/assets/5629ba6d-69fc-4c16-84c9-8be7e449232d)

### No `String`

![error_handling_insert_fixed](https://github.com/user-attachments/assets/6393e2d6-e61a-4558-8ff1-471ff8356c1c)

</details>

For that PR, I just removed the error details entirely, but I figured
I'd try to find a way to keep them around.

## Solution

- Replace the `String` with a helper struct that holds the location, and
only turn it into a string when someone actually wants to print it.
- Replace the `UnsafeWorldCell` with the aforementioned struct.
- Do the same for `QueryEntityError::NoSuchEntity`.

## Benchmarking

This had some interesting performance impact:

<details>
<summary>This PR vs main</summary>


![dne_rework_1](https://github.com/user-attachments/assets/05bf91b4-dddc-4d76-b2c4-41c9d25c7a57)

![dne_rework_2](https://github.com/user-attachments/assets/34aa76b2-d8a7-41e0-9670-c213207e457d)

![dne_rework_3](https://github.com/user-attachments/assets/8b9bd4e4-77c8-45a7-b058-dc0dfd3dd323)

</details>

## Other work

`QueryEntityError::QueryDoesNotMatch` also has an `UnsafeWorldCell`
inside it. This one would be more complicated to rework while keeping
the same functionality.

## Migration Guide

The errors `EntityFetchError::NoSuchEntity` and
`QueryEntityError::NoSuchEntity` now contain an
`EntityDoesNotExistDetails` struct instead of an `UnsafeWorldCell`. If
you were just printing these, they should work identically.

---------

Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
2025-01-05 02:01:01 +00:00
Rob Parrett
651b22f31f
Update typos (#17126)
# Objective

Use the latest version of `typos` and fix the typos that it now detects

# Additional Info

By the way, `typos` has a "low priority typo suggestions issue" where we
can throw typos we find that `typos` doesn't catch.

(This link may go stale) https://github.com/crate-ci/typos/issues/1200
2025-01-03 17:44:26 +00:00
Zachary Harrold
0403948aa2
Remove Implicit std Prelude from no_std Crates (#17086)
# Background

In `no_std` compatible crates, there is often an `std` feature which
will allow access to the standard library. Currently, with the `std`
feature _enabled_, the
[`std::prelude`](https://doc.rust-lang.org/std/prelude/index.html) is
implicitly imported in all modules. With the feature _disabled_, instead
the [`core::prelude`](https://doc.rust-lang.org/core/prelude/index.html)
is implicitly imported. This creates a subtle and pervasive issue where
`alloc` items _may_ be implicitly included (if `std` is enabled), or
must be explicitly included (if `std` is not enabled).

# Objective

- Make the implicit imports for `no_std` crates consistent regardless of
what features are/not enabled.

## Solution

- Replace the `cfg_attr` "double negative" `no_std` attribute with
conditional compilation to _include_ `std` as an external crate.
```rust
// Before
#![cfg_attr(not(feature = "std"), no_std)]

// After
#![no_std]

#[cfg(feature = "std")]
extern crate std;
```
- Fix imports that are currently broken but are only now visible with
the above fix.

## Testing

- CI

## Notes

I had previously used the "double negative" version of `no_std` based on
general consensus that it was "cleaner" within the Rust embedded
community. However, this implicit prelude issue likely was considered
when forming this consensus. I believe the reason why is the items most
affected by this issue are provided by the `alloc` crate, which is
rarely used within embedded but extensively used within Bevy.
2025-01-03 01:58:43 +00:00
arunke
22bf3b9a62
Fix documentation for system set method (#17106)
# Objective

Fix incorrect comment on `IntoSystemSetConfigs::after` likely caused by
copy-paste error. It said "before" instead of "after".

## Solution

Update the comment to the correct text.

## Testing

CI tests pass. This is just updating a comment.
2025-01-02 22:38:26 +00:00
ickshonpe
2931e350b6
reduce nesting in the sparse_set module (#17066)
# Objective

Just being fussy but I hate this `.map(|v|
v.is_some()).unwrap_or(false)` stuff.

## Solution
Reduce it using `and_then`.

---------

Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2025-01-01 23:17:11 +00:00
Sean Kim
294e0db719
Rename track_change_detection flag to track_location (#17075)
# Objective

- As stated in the related issue, this PR is to better align the feature
flag name with what it actually does and the plans for the future.
- Fixes #16852 

## Solution

- Simple find / replace

## Testing

- Local run of `cargo run -p ci`

## Migration Guide

The `track_change_detection` feature flag has been renamed to
`track_location` to better reflect its extended capabilities.
2025-01-01 18:43:47 +00:00
ickshonpe
c817864e4f
Replace map_or(true, _) with is_none_or(_) (#17073)
# Objective

Replace uses of `map_or(true, _)` with the equivalent `is_none_or(_)`.
2025-01-01 04:05:26 +00:00
ickshonpe
7a5a734452
Replace map + unwrap_or(false) with is_some_and (#17067)
# Objective

The `my_option.map(|inner| inner.is_whatever).unwrap_or(false)` pattern
is fragile and ugly.

Replace it with `is_some_and` everywhere.
2024-12-31 20:28:02 +00:00
ickshonpe
c73daea341
Replace map + unwrap_or(true) with is_none_or (#17070)
# Objective

Reduce all varieties of `my_maybe.map(|x| x.is_true).unwrap_or(true)`
using `is_none_or`.
2024-12-31 20:17:03 +00:00
Jonathan Chan Kwan Yin
3c7fbee2d8
Add Mut::clone_from_if_neq (#17019)
# Objective

- Support more ergonomic conditional updates for types that can be
modified by `clone_into`.

## Solution

- Use `ToOwned::clone_into` to copy a reference provided by the caller
in `Mut::clone_from_if_neq`.

## Testing

- See doc tests.
2024-12-31 16:23:01 +00:00
Mike
ac43d5c94f
Convert to fallible system in IntoSystemConfigs (#17051)
# Objective

- #16589 added an enum to switch between fallible and infallible system.
This branching should be unnecessary if we wrap infallible systems in a
function to return `Ok(())`.

## Solution

- Create a wrapper system for `System<(), ()>`s that returns `Ok` on the
call to `run` and `run_unsafe`. The wrapper should compile out, but I
haven't checked.
- I removed the `impl IntoSystemConfigs for BoxedSystem<(), ()>` as I
couldn't figure out a way to keep the impl without double boxing.

## Testing

- ran `many_foxes` example to check if it still runs.

## Migration Guide

- `IntoSystemConfigs` has been removed for `BoxedSystem<(), ()>`. Either
use `InfallibleSystemWrapper` before boxing or make your system return
`bevy::ecs::prelude::Result`.
2024-12-31 00:39:29 +00:00
Zachary Harrold
3f19997096
Added modify_component to EntityWorldMut, DeferredWorld, and World (#16668)
# Objective

- Make working with immutable components more ergonomic
- Assist #16662

## Solution

Added `modify_component` to `World` and `EntityWorldMut`. This method
"removes" a component from an entity, gives a mutable reference to it to
a provided closure, and then "re-inserts" the component back onto the
entity. This replacement triggers the `OnReplace` and `OnInsert` hooks,
but does _not_ cause an archetype move, as the removal is purely
simulated.

## Testing

- Added doc-tests and a unit test.

---

## Showcase

```rust
use bevy_ecs::prelude::*;

/// An immutable component.
#[derive(Component, PartialEq, Eq, Debug)]
#[component(immutable)]
struct Foo(bool);

let mut world = World::default();

let mut entity = world.spawn(Foo(false));

assert_eq!(entity.get::<Foo>(), Some(&Foo(false)));

// Before the closure is executed, the `OnReplace` hooks/observers are triggered
entity.modify_component(|foo: &mut Foo| {
    foo.0 = true;
});
// After the closure is executed, `OnInsert` hooks/observers are triggered

assert_eq!(entity.get::<Foo>(), Some(&Foo(true)));
```

## Notes

- If the component is not available on the entity, the closure and hooks
aren't executed, and `None` is returned. I chose this as an alternative
to returning an error or panicking, but I'm open to changing that based
on feedback.
- This relies on `unsafe`, in particular for accessing the `Archetype`
to trigger hooks. All the unsafe operations are contained within
`DeferredWorld::modify_component`, and I would appreciate that this
function is given special attention to ensure soundness.
- The `OnAdd` hook can never be triggered by this method, since the
component must already be inserted. I have chosen to not trigger
`OnRemove`, as I believe it makes sense that this method is purely a
replacement operation, not an actual removal/insertion.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Malek <50841145+MalekiRe@users.noreply.github.com>
2024-12-31 00:23:44 +00:00
Benjamin Brienen
4460a4d9ed
Use -D warnings in all relevant CI (#17011)
# Objective

Fixes #17009

See:
https://doc.rust-lang.org/stable/clippy/continuous_integration/index.html

## Solution

Add the env

## Testing

CI should start to fail, then I'll fix it.

## Showcase


![image](https://github.com/user-attachments/assets/acd2888f-9fc0-445a-a96a-842ba9f1c6aa)
2024-12-31 00:15:28 +00:00
Zhixing Zhang
9cebc66486
Make 8 methods public and updated input parameter generics for SystemState::build_system_with_input (#17034)
# Objective

- Made certain methods public for advanced use cases. Methods that
returns mutable references are marked as unsafe due to the possibility
of violating internal lifetime constraint assumptions.
- Fixes an issue introduced by #15184
2024-12-30 23:04:14 +00:00
Vic
b78efd339d
Simplify sort/max_by calls (#17048)
# Objective

Some sort calls and `Ord` impls are unnecessarily complex.

## Solution

Rewrite the "match on cmp, if equal do another cmp" as either a
comparison on tuples, or `Ordering::then_with`, depending on whether the
compare keys need construction.

`sort_by` -> `sort_by_key` when symmetrical. Do the same for
`min_by`/`max_by`.

Note that `total_cmp` can only work with `sort_by`, and not on tuples.

When sorting collected query results that contain
`Entity`/`MainEntity`/`RenderEntity` in their `QueryData`, with that
`Entity` in the sort key:
stable -> unstable sort (all queried entities are unique)

If key construction is not simple, switch to `sort_by_cached_key` when
possible.

Sorts that are only performed to discover the maximal element are
replaced by `max_by_key`.

Dedicated comparison functions and structs are removed where simple.

Derive `PartialOrd`/`Ord` when useful.

Misc. closure style inconsistencies.

## Testing
- Existing tests.
2024-12-30 22:59:36 +00:00
JaySpruce
9ac7e17f2e
Refactor hierarchy-related commands to remove structs (#17029)
## Objective

Continuation of #16999.

This PR handles the following:
- Many hierarchy-related commands are wrappers around `World` and
`EntityWorldMut` methods and can be moved to closures:
  - `AddChild`
  - `InsertChildren`
  - `AddChildren`
  - `RemoveChildren`
  - `ClearChildren`
  - `ReplaceChildren`
  - `RemoveParent`
  - `DespawnRecursive`
  - `DespawnChildrenRecursive`
  - `AddChildInPlace`
  - `RemoveParentInPlace`
- `SendEvent` is a wrapper around `World` methods and can be moved to a
closure (and its file deleted).

## Migration Guide

If you were queuing the structs of hierarchy-related commands or
`SendEvent` directly, you will need to change them to the methods
implemented on `EntityCommands` (or `Commands` for `SendEvent`):

| Struct | Method |

|--------------------------------------------------------------------|---------------------------------------------------------------------------------------------|
| `commands.queue(AddChild { child, parent });` |
`commands.entity(parent).add_child(child);` OR
`commands.entity(child).set_parent(parent);` |
| `commands.queue(AddChildren { children, parent });` |
`commands.entity(parent).add_children(children);` |
| `commands.queue(InsertChildren { children, parent });` |
`commands.entity(parent).insert_children(children);` |
| `commands.queue(RemoveChildren { children, parent });` |
`commands.entity(parent).remove_children(children);` |
| `commands.queue(ReplaceChildren { children, parent });` |
`commands.entity(parent).replace_children(children);` |
| `commands.queue(ClearChildren { parent });` |
`commands.entity(parent).clear_children();` |
| `commands.queue(RemoveParent { child });` |
`commands.entity(child).remove_parent()` |
| `commands.queue(DespawnRecursive { entity, warn: true });` |
`commands.entity(entity).despawn_recursive();` |
| `commands.queue(DespawnRecursive { entity, warn: false });` |
`commands.entity(entity).try_despawn_recursive();` |
| `commands.queue(DespawnChildrenRecursive { entity, warn: true });` |
`commands.entity(entity).despawn_descendants();` |
| `commands.queue(DespawnChildrenRecursive { entity, warn: false});` |
`commands.entity(entity).try_despawn_descendants();` |
| `commands.queue(SendEvent { event });` | `commands.send_event(event);`
|
2024-12-30 20:58:03 +00:00
Christian Hughes
b09bbfa905
Remove unsound Clone impl for EntityMutExcept (#17032)
# Objective

`EntityMutExcept` can currently be cloned, which can easily violate
aliasing rules.

## Solution

- Remove the `Clone` impl for `EntityMutExcept`
- Also manually derived `Clone` impl for `EntityRefExcept` so that `B:
Clone` isn't required, and also impl'd `Copy`

## Testing

Compile failure tests would be good for this, but I'm not exactly sure
how to set that up.

## Migration Guide

- `EntityMutExcept` can no-longer be cloned, as this violates Rust's
memory safety rules.
2024-12-30 05:17:46 +00:00
Zachary Harrold
46af46695b
Add no_std support to bevy_input (#16995)
# Objective

- Contributes to #15460

## Solution

- Added the following features:
  - `std` (default)
  - `smol_str` (default)
  - `portable-atomic`
  - `critical-section`
  - `libm`
- Fixed an existing issue where `bevy_reflect` wasn't properly feature
gated.

## Testing

- CI

## Notes

- There were some minor issues with `bevy_math` and `bevy_ecs` noticed
in this PR which I have also resolved here. I can split these out if
desired, but I've left them here for now as they're very small changes
and I don't consider this PR itself to be very controversial.
- `libm`, `portable-atomic`, and `critical-section` are shortcuts to
enable the relevant features in dependencies, making the usage of this
crate on atomically challenged platforms possible and simpler.
- `smol_str` is gated as it doesn't support atomically challenged
platforms (e.g., Raspberry Pi Pico). I have an issue and a
[PR](https://github.com/rust-analyzer/smol_str/pull/91) to discuss this
upstream.
2024-12-29 22:46:30 +00:00
JaySpruce
0f2b2de333
Move some structs that impl Command to methods on World and EntityWorldMut (#16999)
## Objective

Commands were previously limited to structs that implemented `Command`.
Now there are blanket implementations for closures, which (in my
opinion) are generally preferable.

Internal commands within `commands/mod.rs` have been switched from
structs to closures, but there are a number of internal commands in
other areas of the engine that still use structs. I'd like to tidy these
up by moving their implementations to methods on
`World`/`EntityWorldMut` and changing `Commands` to use those methods
through closures.

This PR handles the following:
- `TriggerEvent` and `EmitDynamicTrigger` double as commands and helper
structs, and can just be moved to `World` methods.
- Four structs that enabled insertion/removal of components via
reflection. This functionality shouldn't be exclusive to commands, and
can be added to `EntityWorldMut`.
- Five structs that mostly just wrapped `World` methods, and can be
replaced with closures that do the same thing.

## Solution

- __Observer Triggers__ (`observer/trigger_event.rs` and
`observer/mod.rs`)
- Moved the internals of `TriggerEvent` to the `World` methods that used
it.
  - Replaced `EmitDynamicTrigger` with two `World` methods:
    - `trigger_targets_dynamic`
    - `trigger_targets_dynamic_ref`
- `TriggerTargets` was now the only thing in
`observer/trigger_event.rs`, so it's been moved to `observer/mod.rs` and
`trigger_event.rs` was deleted.
- __Reflection Insert/Remove__ (`reflect/entity_commands.rs`)
- Replaced the following `Command` impls with equivalent methods on
`EntityWorldMut`:
    - `InsertReflect` -> `insert_reflect`
    - `InsertReflectWithRegistry` -> `insert_reflect_with_registry`
    - `RemoveReflect` -> `remove_reflect`
    - `RemoveReflectWithRegistry` -> `remove_reflect_with_registry`
- __System Registration__ (`system/system_registry.rs`)
- The following `Command` impls just wrapped a `World` method and have
been replaced with closures:
    - `RunSystemWith`
    - `UnregisterSystem`
    - `RunSystemCachedWith`
    - `UnregisterSystemCached`
- `RegisterSystem` called a helper function that basically worked as a
constructor for `RegisteredSystem` and made sure it came with a marker
component. That helper function has been replaced with
`RegisteredSystem::new` and a `#[require]`.

## Possible Addition

The extension trait that adds the reflection commands,
`ReflectCommandExt`, isn't strictly necessary; we could just `impl
EntityCommands`. We could even move them to the same files as the main
impls and put it behind a `#[cfg]`.

The PR that added it [had a similar
conversation](https://github.com/bevyengine/bevy/pull/8895#discussion_r1234713671)
and decided to stick with the trait, but we could revisit it here if so
desired.
2024-12-29 22:18:53 +00:00
Benjamin Brienen
8c34f00deb
Fix msrvs (#17012)
# Objective

The rust-versions are out of date.
Fixes #17008

## Solution

Update the values

Cherry-picked from #17006 in case it is controversial

## Testing

Validated locally and in #17006

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-12-29 20:00:19 +00:00
Benjamin Brienen
847c3a1719
Fix random clippy warning (#17010)
# Objective

Follow-up to #16984 

## Solution

Fix the lint

## Testing

```
PS C:\Users\BenjaminBrienen\source\bevy> cargo clippy
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.71s
PS C:\Users\BenjaminBrienen\source\bevy> cargo clippy -p bevy_ecs
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.21s
```
2024-12-29 19:28:59 +00:00
Benjamin Brienen
64efd08e13
Prefer Display over Debug (#16112)
# Objective

Fixes #16104

## Solution

I removed all instances of `:?` and put them back one by one where it
caused an error.

I removed some bevy_utils helper functions that were only used in 2
places and don't add value. See: #11478

## Testing

CI should catch the mistakes

## Migration Guide

`bevy::utils::{dbg,info,warn,error}` were removed. Use
`bevy::utils::tracing::{debug,info,warn,error}` instead.

---------

Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
2024-12-27 00:40:06 +00:00
François Mockers
394e82f4bc
panic on system error (#16979)
# Objective

- First step for #16718 
- #16589 introduced an api that can only ignore errors, which is risky

## Solution

- Panic instead of just ignoring the errors

## Testing

- Changed the `fallible_systems` example to return an error
```
Encountered an error in system `fallible_systems::setup`: TooManyVertices { subdivisions: 300, number_of_resulting_points: 906012 }
Encountered a panic in system `fallible_systems::setup`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
```
2024-12-26 23:44:46 +00:00
Benjamin Brienen
1675d68366
Fix beta CI (#16984)
# Objective

Fixes #16607

## Solution

Satisfy clippy

## Testing

Ran clippy
2024-12-26 22:17:51 +00:00
JaySpruce
1669ca676a
Remove vestigial helper functions for Commands and EntityCommands (#16936)
## Objective

I believe these started as structs, back when that was how commands had
to be implemented. Now they just hide implementation details.

## Solution

Remove the helper functions and move each implementation into its
respective method, except for the ones that actually reduce code
duplication.
2024-12-24 03:07:28 +00:00
Vic
5b899dcc3a
impl EntityBorrow for more types (#16917)
# Objective

Some types like `RenderEntity` and `MainEntity` are just wrappers around
`Entity`, so they should be able to implement
`EntityBorrow`/`TrustedEntityBorrow`. This allows using them with
`EntitySet` functionality.
The `EntityRef` family are more than direct wrappers around `Entity`,
but can still benefit from being unique in a collection.

## Solution

Implement `EntityBorrow` and `TrustedEntityBorrow` for simple `Entity`
newtypes and `EntityRef` types.
These impls are an explicit decision to have the `EntityRef` types
compare like just `Entity`.
`EntityWorldMut` is omitted from this impl, because it explicitly
contains a `&mut World` as well, and we do not ever use more than one at
a time.

Add `EntityBorrow` to the `bevy_ecs` prelude.

## Migration Guide

`NormalizedWindowRef::entity` has been replaced with an
`EntityBorrow::entity` impl.
2024-12-24 02:47:03 +00:00
MiniaczQ
460de77a55
Set panic as default fallible system param behavior (#16638)
# Objective

Fixes: #16578

## Solution

This is a patch fix, proper fix requires a breaking change.

Added `Panic` enum variant and using is as the system meta default.
Warn once behavior can be enabled same way disabling panic (originally
disabling wans) is.

To fix an issue with the current architecture, where **all** combinator
system params get checked together,
combinator systems only check params of the first system.
This will result in old, panicking behavior on subsequent systems and
will be fixed in 0.16.

## Testing

Ran unit tests and `fallible_params` example.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-12-24 02:36:03 +00:00
Oliver Maskery
022c6b1d34
Prevent creation of superfluous empty table (#16935)
# Objective

- To fix a tiny bug in `bevy_ecs::storage::Tables` that, in one case,
means it accidentally allocates an additional "empty" `Table`, resulting
in two "empty" `Table`s:
- The one pre-allocated empty table at index 0 whose index is designed
to match up with `TableId::empty()`
- One extra empty table, at some non-0 index, that does not match up
with `TableId::empty()`.
- This PR aims to prevent this extraneous `Table`, ensuring that
entities with no components in table-storage reliably have their
archetype's table ID be equal to `TableId::empty()`.

## Solution

### Background

The issue occurs because:

- `Tables` contains:
- `tables: Vec<Table>` - The set of all `Table`s allocated in the world.
- `table_ids: HashMap<Box<[ComponentId]>, TableId>` - An index to
rapidly lookup the `Table` in `tables` by a set of `ComponentId`s.
- When `Tables` is constructed it pre-populates the `tables` `Vec` with
an empty `Table`.
- This ensures that the first entry (index 0) is always the `Table` for
entities with no components in table storage.
- In particular, `TableId::empty()` is a utility that returns a
`TableId` of `0`.
- However, the `table_ids` map is not initialised to associate an empty
`[ComponentId]` with `TableId` `0`.
- This means, the first time a structural change tries to access a
`Table` for an archetype with 0 table components:
  - `Tables::get_id_or_insert` is used to retrieve the target `Table`
- The function attempts to lookup the entry in the `table_ids` `HashMap`
whose key is the empty `ComponentId` set
- The empty `Table` created at startup won't be found, because it was
never inserted into `table_ids`
- It will instead create a new table, insert it into the `HashMap`
(preventing further instances of this issue), and return it.

### Changes

- I considered simply initialising the `table_ids` `HashMap` to know
about the pre-allocated `Table`
- However, I ended up using the proposed solution discussed on Discord
[#ecs-dev](https://discord.com/channels/691052431525675048/749335865876021248/1320430933152759958):
- Make `Tables::get_id_or_insert` simply early-exit if the requested
`component_ids` was empty.
- This avoids unnecessarily hashing the empty slice and looking it up in
the `HashMap`.
- The `table_ids` `HashMap` is not exposed outside this struct, and is
only used within `get_id_or_insert`, so it seems wasteful to defensively
populate it with the empty `Table`.

## Testing

This is my first Bevy contribution, so I don't really know the processes
that well. That said:
- I have introduced a little test that exercises the original issue and
shows that it is now resolved.
- I have run the `bevy_ecs` tests locally, so I have reasonable
confidence I haven't broken that.
- I haven't run any further test suites, mostly as when I tried to run
test suites for the whole project it filled my entire SSD with >600GB of
target directory output 😱😱😱
2024-12-22 23:04:32 +00:00
urben1680
cf21d9a37e
Remove unused generic in DeferredWorld::trigger (#16911)
Fixing what I just noticed.

## Migration Guide

- Remove the generic parameter when calling this method
2024-12-21 04:15:22 +00:00
Vic
8ac90ac542
make EntityHashMap and EntityHashSet proper types (#16912)
# Objective

`EntityHashMap` and `EntityHashSet` iterators do not implement
`EntitySetIterator`.

## Solution

Make them newtypes instead of aliases. The methods that create the
iterators can then produce their own newtypes that carry the `Hasher`
generic and implement `EntitySetIterator`. Functionality remains the
same otherwise.
There are some other small benefits, f.e. the removal of `with_hasher`
associated functions, and the ability to implement more traits
ourselves.

`MainEntityHashMap` and `MainEntityHashSet` are currently left as the
previous type aliases, because supporting general `TrustedEntityBorrow`
hashing is more complex. However, it can also be done.

## Testing

Pre-existing `EntityHashMap` tests.

## Migration Guide

Users of `with_hasher` and `with_capacity_and_hasher` on
`EntityHashMap`/`Set` must now use `new` and `with_capacity`
respectively.
If the non-newtyped versions are required, they can be obtained via
`Deref`, `DerefMut` or `into_inner` calls.
2024-12-20 20:55:45 +00:00
Zachary Harrold
21786632c3
Remove bevy_core (#16897)
# Objective

- Fixes #16892

## Solution

- Removed `TypeRegistryPlugin` (`Name` is now automatically registered
with a default `App`)
- Moved `TaskPoolPlugin` to `bevy_app`
- Moved `FrameCountPlugin` to `bevy_diagnostic`
- Deleted now-empty `bevy_core`

## Testing

- CI

## Migration Guide

- `TypeRegistryPlugin` no longer exists. If you can't use a default
`App` but still need `Name` registered, do so manually with
`app.register_type::<Name>()`.
- References to `TaskPoolPlugin` and associated types will need to
import it from `bevy_app` instead of `bevy_core`
- References to `FrameCountPlugin` and associated types will need to
import it from `bevy_diagnostic` instead of `bevy_core`

## Notes

This strategy was agreed upon by Cart and several other members in
[Discord](https://discord.com/channels/691052431525675048/692572690833473578/1319137218312278077).
2024-12-19 18:36:51 +00:00
Zachary Harrold
d4b07a5114
Move Name out of bevy_core (#16894)
# Objective

- Contributes to #16892

## Solution

- Moved `Name` and `NameOrEntity` into `bevy_ecs::name`, and added them
to the prelude.

## Testing

- CI

## Migration Guide

If you were importing `Name` or `NameOrEntity` from `bevy_core`, instead
import from `bevy_ecs::name`.

---------

Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com>
2024-12-19 02:45:16 +00:00