Commit graph

1326 commits

Author SHA1 Message Date
Jonathan Chan Kwan Yin
e66cd484a7
Add insert_by_id and try_insert_by_id to EntityCommands (#14283)
# Objective

- Allow queuing insertion of dynamic components to an existing entity

## Solution

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

## Testing

TODO

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

## Alternatives

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

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

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

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

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

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Felix Rath <felixm.rath@gmail.com>
2024-07-15 23:29:13 +00:00
Brezak
6522795889
Specify test group names in github summary for compile fail tests (#14330)
# Objective

The github action summary titles every compile test group as
`compile_fail_utils`.


![image](https://github.com/user-attachments/assets/9d00a113-6772-430c-8da9-bffe6a60a8f8)

## Solution

Manually specify group names for compile fail tests.

## Testing

- Wait for compile fail tests to run.
- Observe the generated summary.
2024-07-15 16:13:03 +00:00
SpecificProtagonist
d276525350
Allow non-static trigger targets (#14327)
# Objective

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

## Solution

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

## Testing

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

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

## Solution

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

Fixes #14202

## Solution

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

## Testing

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

---

## Changelog

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

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

## Solution

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

## Testing

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

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

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

## Solution

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

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

## Testing

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

## Changelog

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

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

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

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

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

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

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

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

---------

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

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

## Solution

- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
2024-07-11 13:08:31 +00:00
Blake Bedford
2414311079
Fixed #14248 and other URL issues (#14276)
# Objective

Fixes #14248 and other URL issues.

## Solution

- Describe the solution used to achieve the objective above.
Removed the random #s in the URL. Led users to the wrong page. For
example, https://bevyengine.org/learn/errors/#b0003 takes users to
https://bevyengine.org/learn/errors/introduction, which is not the right
page. Removing the #s fixes it.

## Testing

- Did you test these changes? If so, how?
I pasted the URL into my address bar and it took me to the right place.

- Are there any parts that need more testing?
No
2024-07-11 12:01:49 +00:00
Bob Gardner
ec1aa48fc6
Created an EventMutator for when you want to mutate an event before reading (#13818)
# Objective

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

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

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

## Solution

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

## Testing

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

## Migration Guide

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

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

---------

Co-authored-by: poopy <gonesbird@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-07-08 14:53:06 +00:00
github-actions[bot]
8df10d2713
Bump Version after Release (#14219)
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>
2024-07-08 12:54:08 +00:00
Mike
33ea3b9f7d
use Display for entity id in log_components (#14164)
# Objective

- Cleanup a doubled `Entity` in log components

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

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

---------

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

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

## Solution

Added 3 new attributes to the `Component` macro.

## Testing

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

---

---------

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

The bounds for query iterators are quite intimidating.

## Solution

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

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

## Solution

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

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

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

## Solution

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

## Testing

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

---------

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

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

## Solution

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

## Testing

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

---------

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

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

## Solution

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

## Testing

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

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

## Solution

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

`QueryIter::sort_unstable_by_key` is missing.

## Solution

Add `QueryIter::sort_unstable_by_key`.

## Testing

Added the new method to existing test.

## Changelog

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

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

## Solution

Annotate the method with `#[must_use]`

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

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

# Solution

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

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

---------

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

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

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

## Solution

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

## Testing

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

---------

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

- Fix issue #13821  

## Solution

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

## Testing

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

---------

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

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

## Solution

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

This _should_ be backported to 0.14 before release.

---

## Changelog

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

Stumbled on one of these and went digging for more

## Solution

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

Fixes #13933.

## Solution

Changed the return type.

## Testing

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

---

## Migration Guide

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

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

Fixes #13917 

## Solution

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

## Testing

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

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

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

## Solution

- Change `item` to `items`

## Testing

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

---

## Changelog

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

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

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

- Fixes #13885 

## Solution

- Update the flags correctly on archetype creation

## Testing

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

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

## Solution

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

## Testing

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

## Profiling

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


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

</details>

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

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

## Solution

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

---

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

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

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

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

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

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

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

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

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

Additionally, Observers don't _need_ entity targets:

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

commands.trigger(Quit);
```

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

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

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

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

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

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

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

---------

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

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

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

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

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

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

## Solution

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

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

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

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

## Testing

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

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

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

## Outstanding

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

---------

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

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

## Solution

- Fix them

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

This reverts commit 5cfb063d4a.

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

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

## Solution

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

## Testing

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

# Objective

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

## Solution

- Don't call clear_trackers an extra time.

## Testing

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

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

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

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

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

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

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

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

## Solution

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

- My attempt at fulfilling #13629.

## Solution

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

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

## Testing

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

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

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

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

## Changelog

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

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

## Migration Guide

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

---------

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

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

## Solution

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

- Fixes #13703

## Solution

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

## Testing

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

---

## Changelog

- Added `mappings` to `EntityMapper` trait.

## Migration Guide

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

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

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

## Notes

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

---------

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

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

## Solution

We just take slices and return Vectors.

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

## Testing

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

Fix a few typos I spotted while looking over #13347

## Solution

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

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

## Solution

- Re-adds #13347.

Co-authored-by: Zachary Harrold <zac@harrold.com.au>
Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
2024-06-04 00:31:34 +00:00
Brandon Reinhart
7570c9f3d2
Map entities from a resource when written to the world. (#13650)
# Objective

- Fix #10958 by performing entity mapping on the entities inside of
resources.

## Solution

- Resources can reflect(MapEntitiesResource) and impl MapEntities to get
access to the mapper during the world insert of the scene.

## Testing

- A test resource_entity_map_maps_entities confirms the desired
behavior.

## Changelog

- Added reflect(MapEntitiesResource) for mapping entities on Resources
in a DynamicScene.

fixes 10958
2024-06-03 16:33:24 +00:00
Gonçalo Rica Pais da Silva
36f2542f63
feat: Reflection implementations on Identifier (#13648)
# Objective

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

## Solution

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

## Testing

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

---

## Changelog

### Added

- Reflection implementations on `Identifier`.
2024-06-03 16:33:14 +00:00