# Objective
Unblock #18162.
#15396 added the `'s` lifetime to `QueryData::Item` to make it possible
for query items to borrow from the state. The state isn't passed
directly to `QueryData::fetch()`, so it also added the `'s` lifetime to
`WorldQuery::Fetch` so that we can pass the borrows through there.
Unfortunately, having `WorldQuery::Fetch` borrow from the state makes it
impossible to have owned state, because we store the state and the
`Fetch` in the same `struct` during iteration.
## Solution
Undo the change to add the `'s` lifetime to `WorldQuery::Fetch`.
Instead, add a `&'s Self::State` parameter to `QueryData::fetch()` and
`QueryFilter::filter_fetch()` so that borrows from the state can be
passed directly to query items.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Emerson Coskey <emerson@coskey.dev>
# Objective
- Fixes#19627
- Tackles part of #19644
- Supersedes #19629
- `Window` has become a very very very big component
- As such, our change detection does not *really* work on it, as e.g.
moving the mouse will cause a change for the entire window
- We circumvented this with a cache
- But, some things *shouldn't* be cached as they can be changed from
outside the user's control, notably the cursor grab mode on web
- So, we need to disable the cache for that
- But because change detection is broken, that would result in the
cursor grab mode being set every frame the mouse is moved
- That is usually *not* what a dev wants, as it forces the cursor to be
locked even when the end-user is trying to free the cursor on the
browser
- the cache in this situation is invalid due to #8949
## Solution
- Split `Window` into multiple components, each with working change
detection
- Disable caching of the cursor grab mode
- This will only attempt to force the grab mode when the `CursorOptions`
were touched by the user, which is *much* rarer than simply moving the
mouse.
- If this PR is merged, I'll do the exact same for the other
constituents of `Window` as a follow-up
## Testing
- Ran all the changed examples
# Objective
- compute_matrix doesn't compute anything, it just puts an Affine3A into
a Mat4. the name is inaccurate
## Solution
- rename it to conform with to_isometry (which, ironically, does compute
a decomposition which is rather expensive)
## Testing
- Its a rename. If it compiles, its good to go
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Improve the performance of `FilteredEntity(Ref|Mut)` and
`Entity(Ref|Mut)Except`.
`FilteredEntityRef` needs an `Access<ComponentId>` to determine what
components it can access. There is one stored in the query state, but
query items cannot borrow from the state, so it has to `clone()` the
access for each row. Cloning the access involves memory allocations and
can be expensive.
## Solution
Let query items borrow from their query state.
Add an `'s` lifetime to `WorldQuery::Item` and `WorldQuery::Fetch`,
similar to the one in `SystemParam`, and provide `&'s Self::State` to
the fetch so that it can borrow from the state.
Unfortunately, there are a few cases where we currently return query
items from temporary query states: the sorted iteration methods create a
temporary state to query the sort keys, and the
`EntityRef::components<Q>()` methods create a temporary state for their
query.
To allow these to continue to work with most `QueryData`
implementations, introduce a new subtrait `ReleaseStateQueryData` that
converts a `QueryItem<'w, 's>` to `QueryItem<'w, 'static>`, and is
implemented for everything except `FilteredEntity(Ref|Mut)` and
`Entity(Ref|Mut)Except`.
`#[derive(QueryData)]` will generate `ReleaseStateQueryData`
implementations that apply when all of the subqueries implement
`ReleaseStateQueryData`.
This PR does not actually change the implementation of
`FilteredEntity(Ref|Mut)` or `Entity(Ref|Mut)Except`! That will be done
as a follow-up PR so that the changes are easier to review. I have
pushed the changes as chescock/bevy#5.
## Testing
I ran performance traces of many_foxes, both against main and against
chescock/bevy#5, both including #15282. These changes do appear to make
generalized animation a bit faster:
(Red is main, yellow is chescock/bevy#5)

## Migration Guide
The `WorldQuery::Item` and `WorldQuery::Fetch` associated types and the
`QueryItem` and `ROQueryItem` type aliases now have an additional
lifetime parameter corresponding to the `'s` lifetime in `Query`. Manual
implementations of `WorldQuery` will need to update the method
signatures to include the new lifetimes. Other uses of the types will
need to be updated to include a lifetime parameter, although it can
usually be passed as `'_`. In particular, `ROQueryItem` is used when
implementing `RenderCommand`.
Before:
```rust
fn render<'w>(
item: &P,
view: ROQueryItem<'w, Self::ViewQuery>,
entity: Option<ROQueryItem<'w, Self::ItemQuery>>,
param: SystemParamItem<'w, '_, Self::Param>,
pass: &mut TrackedRenderPass<'w>,
) -> RenderCommandResult;
```
After:
```rust
fn render<'w>(
item: &P,
view: ROQueryItem<'w, '_, Self::ViewQuery>,
entity: Option<ROQueryItem<'w, '_, Self::ItemQuery>>,
param: SystemParamItem<'w, '_, Self::Param>,
pass: &mut TrackedRenderPass<'w>,
) -> RenderCommandResult;
```
---
Methods on `QueryState` that take `&mut self` may now result in
conflicting borrows if the query items capture the lifetime of the
mutable reference. This affects `get()`, `iter()`, and others. To fix
the errors, first call `QueryState::update_archetypes()`, and then
replace a call `state.foo(world, param)` with
`state.query_manual(world).foo_inner(param)`. Alternately, you may be
able to restructure the code to call `state.query(world)` once and then
make multiple calls using the `Query`.
Before:
```rust
let mut state: QueryState<_, _> = ...;
let d1 = state.get(world, e1);
let d2 = state.get(world, e2); // Error: cannot borrow `state` as mutable more than once at a time
println!("{d1:?}");
println!("{d2:?}");
```
After:
```rust
let mut state: QueryState<_, _> = ...;
state.update_archetypes(world);
let d1 = state.get_manual(world, e1);
let d2 = state.get_manual(world, e2);
// OR
state.update_archetypes(world);
let d1 = state.query(world).get_inner(e1);
let d2 = state.query(world).get_inner(e2);
// OR
let query = state.query(world);
let d1 = query.get_inner(e1);
let d1 = query.get_inner(e2);
println!("{d1:?}");
println!("{d2:?}");
```
# Objective
Getting access to the original target of an entity-event is really
helpful when working with bubbled / propagated events.
`bevy_picking` special-cases this, but users have requested this for all
sorts of bubbled events.
The existing naming convention was also very confusing. Fixes
https://github.com/bevyengine/bevy/issues/17112, but also see #18982.
## Solution
1. Rename `ObserverTrigger::target` -> `current_target`.
1. Store `original_target: Option<Entity>` in `ObserverTrigger`.
1. Wire it up so this field gets set correctly.
1. Remove the `target` field on the `Pointer` events from
`bevy_picking`.
Closes https://github.com/bevyengine/bevy/pull/18710, which attempted
the same thing. Thanks @emfax!
## Testing
I've modified an existing test to check that the entities returned
during event bubbling / propagation are correct.
## Notes to reviewers
It's a little weird / sad that you can no longer access this infromation
via the buffered events for `Pointer`. That said, you already couldn't
access any bubbled target. We should probably remove the `BufferedEvent`
form of `Pointer` to reduce confusion and overhead, but I didn't want to
do so here.
Observer events can be trivially converted into buffered events (write
an observer with an EventWriter), and I suspect that that is the better
migration if you want the controllable timing or performance
characteristics of buffered events for your specific use case.
## Future work
It would be nice to not store this data at all (and not expose any
methods) if propagation was disabled. That involves more trait
shuffling, and I don't think we should do it here for reviewability.
---------
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Closes#19564.
The current `Event` trait looks like this:
```rust
pub trait Event: Send + Sync + 'static {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
```
The `Event` trait is used by both buffered events
(`EventReader`/`EventWriter`) and observer events. If they are observer
events, they can optionally be targeted at specific `Entity`s or
`ComponentId`s, and can even be propagated to other entities.
However, there has long been a desire to split the trait semantically
for a variety of reasons, see #14843, #14272, and #16031 for discussion.
Some reasons include:
- It's very uncommon to use a single event type as both a buffered event
and targeted observer event. They are used differently and tend to have
distinct semantics.
- A common footgun is using buffered events with observers or event
readers with observer events, as there is no type-level error that
prevents this kind of misuse.
- #19440 made `Trigger::target` return an `Option<Entity>`. This
*seriously* hurts ergonomics for the general case of entity observers,
as you need to `.unwrap()` each time. If we could statically determine
whether the event is expected to have an entity target, this would be
unnecessary.
There's really two main ways that we can categorize events: push vs.
pull (i.e. "observer event" vs. "buffered event") and global vs.
targeted:
| | Push | Pull |
| ------------ | --------------- | --------------------------- |
| **Global** | Global observer | `EventReader`/`EventWriter` |
| **Targeted** | Entity observer | - |
There are many ways to approach this, each with their tradeoffs.
Ultimately, we kind of want to split events both ways:
- A type-level distinction between observer events and buffered events,
to prevent people from using the wrong kind of event in APIs
- A statically designated entity target for observer events to avoid
accidentally using untargeted events for targeted APIs
This PR achieves these goals by splitting event traits into `Event`,
`EntityEvent`, and `BufferedEvent`, with `Event` being the shared trait
implemented by all events.
## `Event`, `EntityEvent`, and `BufferedEvent`
`Event` is now a very simple trait shared by all events.
```rust
pub trait Event: Send + Sync + 'static {
// Required for observer APIs
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
```
You can call `trigger` for *any* event, and use a global observer for
listening to the event.
```rust
#[derive(Event)]
struct Speak {
message: String,
}
// ...
app.add_observer(|trigger: On<Speak>| {
println!("{}", trigger.message);
});
// ...
commands.trigger(Speak {
message: "Y'all like these reworked events?".to_string(),
});
```
To allow an event to be targeted at entities and even propagated
further, you can additionally implement the `EntityEvent` trait:
```rust
pub trait EntityEvent: Event {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
}
```
This lets you call `trigger_targets`, and to use targeted observer APIs
like `EntityCommands::observe`:
```rust
#[derive(Event, EntityEvent)]
#[entity_event(traversal = &'static ChildOf, auto_propagate)]
struct Damage {
amount: f32,
}
// ...
let enemy = commands.spawn((Enemy, Health(100.0))).id();
// Spawn some armor as a child of the enemy entity.
// When the armor takes damage, it will bubble the event up to the enemy.
let armor_piece = commands
.spawn((ArmorPiece, Health(25.0), ChildOf(enemy)))
.observe(|trigger: On<Damage>, mut query: Query<&mut Health>| {
// Note: `On::target` only exists because this is an `EntityEvent`.
let mut health = query.get(trigger.target()).unwrap();
health.0 -= trigger.amount();
});
commands.trigger_targets(Damage { amount: 10.0 }, armor_piece);
```
> [!NOTE]
> You *can* still also trigger an `EntityEvent` without targets using
`trigger`. We probably *could* make this an either-or thing, but I'm not
sure that's actually desirable.
To allow an event to be used with the buffered API, you can implement
`BufferedEvent`:
```rust
pub trait BufferedEvent: Event {}
```
The event can then be used with `EventReader`/`EventWriter`:
```rust
#[derive(Event, BufferedEvent)]
struct Message(String);
fn write_hello(mut writer: EventWriter<Message>) {
writer.write(Message("I hope these examples are alright".to_string()));
}
fn read_messages(mut reader: EventReader<Message>) {
// Process all buffered events of type `Message`.
for Message(message) in reader.read() {
println!("{message}");
}
}
```
In summary:
- Need a basic event you can trigger and observe? Derive `Event`!
- Need the event to be targeted at an entity? Derive `EntityEvent`!
- Need the event to be buffered and support the
`EventReader`/`EventWriter` API? Derive `BufferedEvent`!
## Alternatives
I'll now cover some of the alternative approaches I have considered and
briefly explored. I made this section collapsible since it ended up
being quite long :P
<details>
<summary>Expand this to see alternatives</summary>
### 1. Unified `Event` Trait
One option is not to have *three* separate traits (`Event`,
`EntityEvent`, `BufferedEvent`), and to instead just use associated
constants on `Event` to determine whether an event supports targeting
and buffering or not:
```rust
pub trait Event: Send + Sync + 'static {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
const TARGETED: bool = false;
const BUFFERED: bool = false;
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
```
Methods can then use bounds like `where E: Event<TARGETED = true>` or
`where E: Event<BUFFERED = true>` to limit APIs to specific kinds of
events.
This would keep everything under one `Event` trait, but I don't think
it's necessarily a good idea. It makes APIs harder to read, and docs
can't easily refer to specific types of events. You can also create
weird invariants: what if you specify `TARGETED = false`, but have
`Traversal` and/or `AUTO_PROPAGATE` enabled?
### 2. `Event` and `Trigger`
Another option is to only split the traits between buffered events and
observer events, since that is the main thing people have been asking
for, and they have the largest API difference.
If we did this, I think we would need to make the terms *clearly*
separate. We can't really use `Event` and `BufferedEvent` as the names,
since it would be strange that `BufferedEvent` doesn't implement
`Event`. Something like `ObserverEvent` and `BufferedEvent` could work,
but it'd be more verbose.
For this approach, I would instead keep `Event` for the current
`EventReader`/`EventWriter` API, and call the observer event a
`Trigger`, since the "trigger" terminology is already used in the
observer context within Bevy (both as a noun and a verb). This is also
what a long [bikeshed on
Discord](https://discord.com/channels/691052431525675048/749335865876021248/1298057661878898791)
seemed to land on at the end of last year.
```rust
// For `EventReader`/`EventWriter`
pub trait Event: Send + Sync + 'static {}
// For observers
pub trait Trigger: Send + Sync + 'static {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
const TARGETED: bool = false;
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
```
The problem is that "event" is just a really good term for something
that "happens". Observers are rapidly becoming the more prominent API,
so it'd be weird to give them the `Trigger` name and leave the good
`Event` name for the less common API.
So, even though a split like this seems neat on the surface, I think it
ultimately wouldn't really work. We want to keep the `Event` name for
observer events, and there is no good alternative for the buffered
variant. (`Message` was suggested, but saying stuff like "sends a
collision message" is weird.)
### 3. `GlobalEvent` + `TargetedEvent`
What if instead of focusing on the buffered vs. observed split, we
*only* make a distinction between global and targeted events?
```rust
// A shared event trait to allow global observers to work
pub trait Event: Send + Sync + 'static {
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
// For buffered events and non-targeted observer events
pub trait GlobalEvent: Event {}
// For targeted observer events
pub trait TargetedEvent: Event {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
}
```
This is actually the first approach I implemented, and it has the neat
characteristic that you can only use non-targeted APIs like `trigger`
with a `GlobalEvent` and targeted APIs like `trigger_targets` with a
`TargetedEvent`. You have full control over whether the entity should or
should not have a target, as they are fully distinct at the type-level.
However, there's a few problems:
- There is no type-level indication of whether a `GlobalEvent` supports
buffered events or just non-targeted observer events
- An `Event` on its own does literally nothing, it's just a shared trait
required to make global observers accept both non-targeted and targeted
events
- If an event is both a `GlobalEvent` and `TargetedEvent`, global
observers again have ambiguity on whether an event has a target or not,
undermining some of the benefits
- The names are not ideal
### 4. `Event` and `EntityEvent`
We can fix some of the problems of Alternative 3 by accepting that
targeted events can also be used in non-targeted contexts, and simply
having the `Event` and `EntityEvent` traits:
```rust
// For buffered events and non-targeted observer events
pub trait Event: Send + Sync + 'static {
fn register_component_id(world: &mut World) -> ComponentId { ... }
fn component_id(world: &World) -> Option<ComponentId> { ... }
}
// For targeted observer events
pub trait EntityEvent: Event {
type Traversal: Traversal<Self>;
const AUTO_PROPAGATE: bool = false;
}
```
This is essentially identical to this PR, just without a dedicated
`BufferedEvent`. The remaining major "problem" is that there is still
zero type-level indication of whether an `Event` event *actually*
supports the buffered API. This leads us to the solution proposed in
this PR, using `Event`, `EntityEvent`, and `BufferedEvent`.
</details>
## Conclusion
The `Event` + `EntityEvent` + `BufferedEvent` split proposed in this PR
aims to solve all the common problems with Bevy's current event model
while keeping the "weirdness" factor minimal. It splits in terms of both
the push vs. pull *and* global vs. targeted aspects, while maintaining a
shared concept for an "event".
### Why I Like This
- The term "event" remains as a single concept for all the different
kinds of events in Bevy.
- Despite all event types being "events", they use fundamentally
different APIs. Instead of assuming that you can use an event type with
any pattern (when only one is typically supported), you explicitly opt
in to each one with dedicated traits.
- Using separate traits for each type of event helps with documentation
and clearer function signatures.
- I can safely make assumptions on expected usage.
- If I see that an event is an `EntityEvent`, I can assume that I can
use `observe` on it and get targeted events.
- If I see that an event is a `BufferedEvent`, I can assume that I can
use `EventReader` to read events.
- If I see both `EntityEvent` and `BufferedEvent`, I can assume that
both APIs are supported.
In summary: This allows for a unified concept for events, while limiting
the different ways to use them with opt-in traits. No more guess-work
involved when using APIs.
### Problems?
- Because `BufferedEvent` implements `Event` (for more consistent
semantics etc.), you can still use all buffered events for non-targeted
observers. I think this is fine/good. The important part is that if you
see that an event implements `BufferedEvent`, you know that the
`EventReader`/`EventWriter` API should be supported. Whether it *also*
supports other APIs is secondary.
- I currently only support `trigger_targets` for an `EntityEvent`.
However, you can technically target components too, without targeting
any entities. I consider that such a niche and advanced use case that
it's not a huge problem to only support it for `EntityEvent`s, but we
could also split `trigger_targets` into `trigger_entities` and
`trigger_components` if we wanted to (or implement components as
entities :P).
- You can still trigger an `EntityEvent` *without* targets. I consider
this correct, since `Event` implements the non-targeted behavior, and
it'd be weird if implementing another trait *removed* behavior. However,
it does mean that global observers for entity events can technically
return `Entity::PLACEHOLDER` again (since I got rid of the
`Option<Entity>` added in #19440 for ergonomics). I think that's enough
of an edge case that it's not a huge problem, but it is worth keeping in
mind.
- ~~Deriving both `EntityEvent` and `BufferedEvent` for the same type
currently duplicates the `Event` implementation, so you instead need to
manually implement one of them.~~ Changed to always requiring `Event` to
be derived.
## Related Work
There are plans to implement multi-event support for observers,
especially for UI contexts. [Cart's
example](https://github.com/bevyengine/bevy/issues/14649#issuecomment-2960402508)
API looked like this:
```rust
// Truncated for brevity
trigger: Trigger<(
OnAdd<Pressed>,
OnRemove<Pressed>,
OnAdd<InteractionDisabled>,
OnRemove<InteractionDisabled>,
OnInsert<Hovered>,
)>,
```
I believe this shouldn't be in conflict with this PR. If anything, this
PR might *help* achieve the multi-event pattern for entity observers
with fewer footguns: by statically enforcing that all of these events
are `EntityEvent`s in the context of `EntityCommands::observe`, we can
avoid misuse or weird cases where *some* events inside the trigger are
targeted while others are not.
# Objective
- A step towards #19024.
- Allow `ReflectAsset` to work with any `AssetId` not just `Handle`.
- `ReflectAsset::ids()` returns an iterator of `AssetId`s, but then
there's no way to use these ids, since all the other APIs in
`ReflectAsset` require a handle (and we don't have a reflect way to get
the handle).
## Solution
- Replace the `UntypedHandle` argument in `ReflectAsset` methods with
`impl Into<UntypedAssetId>`.
- This matches the regular asset API.
- This allows `ReflectAsset::ids()` to be more useful.
## Testing
- None.
Follow-up of #19274.
Make the `check_change_tick` methods, of which some are now public, take
`CheckChangeTicks` to make it obvious where this tick comes from, see
other PR.
This also affects the `System` trait, hence the many changed files.
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
# Objective
Reduce memory usage by storing fewer copies of
`FilteredAccessSet<ComponentId>`.
Currently, the `System` trait exposes the `component_access_set` for the
system, which is used by the multi-threaded executor to determine which
systems can run concurrently. But because it is available on the trait,
it needs to be stored for *every* system, even ones that are not run by
the executor! In particular, it is never needed for observers, or for
the inner systems in a `PipeSystem` or `CombinatorSystem`.
## Solution
Instead of exposing the access from a method on `System`, return it from
`System::initialize`. Since it is still needed during scheduling, store
the access alongside the boxed system in the schedule.
That's not quite enough for systems built using `SystemParamBuilder`s,
though. Those calculate the access in `SystemParamBuilder::build`, which
happens earlier than `System::initialize`. To handle those, we separate
`SystemParam::init_state` into `init_state`, which creates the state
value, and `init_access`, which calculates the access. This lets
`System::initialize` call `init_access` on a state that was provided by
the builder.
An additional benefit of that separation is that it removes the need to
duplicate access checks between `SystemParamBuilder::build` and
`SystemParam::init_state`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Currently, the observer API looks like this:
```rust
app.add_observer(|trigger: Trigger<Explode>| {
info!("Entity {} exploded!", trigger.target());
});
```
Future plans for observers also include "multi-event observers" with a
trigger that looks like this (see [Cart's
example](https://github.com/bevyengine/bevy/issues/14649#issuecomment-2960402508)):
```rust
trigger: Trigger<(
OnAdd<Pressed>,
OnRemove<Pressed>,
OnAdd<InteractionDisabled>,
OnRemove<InteractionDisabled>,
OnInsert<Hovered>,
)>,
```
In scenarios like this, there is a lot of repetition of `On`. These are
expected to be very high-traffic APIs especially in UI contexts, so
ergonomics and readability are critical.
By renaming `Trigger` to `On`, we can make these APIs read more cleanly
and get rid of the repetition:
```rust
app.add_observer(|trigger: On<Explode>| {
info!("Entity {} exploded!", trigger.target());
});
```
```rust
trigger: On<(
Add<Pressed>,
Remove<Pressed>,
Add<InteractionDisabled>,
Remove<InteractionDisabled>,
Insert<Hovered>,
)>,
```
Names like `On<Add<Pressed>>` emphasize the actual event listener nature
more than `Trigger<OnAdd<Pressed>>`, and look cleaner. This *also* frees
up the `Trigger` name if we want to use it for the observer event type,
splitting them out from buffered events (bikeshedding this is out of
scope for this PR though).
For prior art:
[`bevy_eventlistener`](https://github.com/aevyrie/bevy_eventlistener)
used
[`On`](https://docs.rs/bevy_eventlistener/latest/bevy_eventlistener/event_listener/struct.On.html)
for its event listener type. Though in our case, the observer is the
event listener, and `On` is just a type containing information about the
triggered event.
## Solution
Steal from `bevy_event_listener` by @aevyrie and use `On`.
- Rename `Trigger` to `On`
- Rename `OnAdd` to `Add`
- Rename `OnInsert` to `Insert`
- Rename `OnReplace` to `Replace`
- Rename `OnRemove` to `Remove`
- Rename `OnDespawn` to `Despawn`
## Discussion
### Naming Conflicts??
Using a name like `Add` might initially feel like a very bad idea, since
it risks conflict with `core::ops::Add`. However, I don't expect this to
be a big problem in practice.
- You rarely need to actually implement the `Add` trait, especially in
modules that would use the Bevy ECS.
- In the rare cases where you *do* get a conflict, it is very easy to
fix by just disambiguating, for example using `ops::Add`.
- The `Add` event is a struct while the `Add` trait is a trait (duh), so
the compiler error should be very obvious.
For the record, renaming `OnAdd` to `Add`, I got exactly *zero* errors
or conflicts within Bevy itself. But this is of course not entirely
representative of actual projects *using* Bevy.
You might then wonder, why not use `Added`? This would conflict with the
`Added` query filter, so it wouldn't work. Additionally, the current
naming convention for observer events does not use past tense.
### Documentation
This does make documentation slightly more awkward when referring to
`On` or its methods. Previous docs often referred to `Trigger::target`
or "sends a `Trigger`" (which is... a bit strange anyway), which would
now be `On::target` and "sends an observer `Event`".
You can see the diff in this PR to see some of the effects. I think it
should be fine though, we may just need to reword more documentation to
read better.
# Objective
#19366 implemented core button widgets, which included the `Depressed`
state component.
`Depressed` was chosen instead of `Pressed` to avoid conflict with the
`Pointer<Pressed>` event, but it is problematic and awkward in many
ways:
- Using the word "depressed" for such a high-traffic type is not great
due to the obvious connection to "depressed" as in depression.
- "Depressed" is not what I would search for if I was looking for a
component like this, and I'm not aware of any other engine or UI
framework using the term.
- `Depressed` is not a very natural pair to the `Pointer<Pressed>`
event.
- It might be because I'm not a native English speaker, but I have very
rarely heard someone say "a button is depressed". Seeing it, my mind
initially goes from "depression??" to "oh, de-pressed, meaning released"
and definitely not "is pressed", even though that *is* also a valid
meaning for it.
A related problem is that the current `Pointer<Pressed>` and
`Pointer<Released>` event names use a different verb tense than all of
our other observer events such as `Pointer<Click>` or
`Pointer<DragStart>`. By fixing this and renaming `Pressed` (and
`Released`), we can then use `Pressed` instead of `Depressed` for the
state component.
Additionally, the `IsHovered` and `IsDirectlyHovered` components added
in #19366 use an inconsistent naming; the other similar components don't
use an `Is` prefix. It also makes query filters like `Has<IsHovered>`
and `With<IsHovered>` a bit more awkward.
This is partially related to Cart's [picking concept
proposal](https://gist.github.com/cart/756e48a149db2838028be600defbd24a?permalink_comment_id=5598154).
## Solution
- Rename `Pointer<Pressed>` to `Pointer<Press>`
- Rename `Pointer<Released>` to `Pointer<Release>`
- Rename `Depressed` to `Pressed`
- Rename `IsHovered` to `Hovered`
- Rename `IsDirectlyHovered` to `DirectlyHovered`
# Objective
As discussed in #19285, some of our names conflict. `Entry` in bevy_ecs
is one of those overly general names.
## Solution
Rename this type (and the related types) to `ComponentEntry`.
---------
Co-authored-by: urben1680 <55257931+urben1680@users.noreply.github.com>
# Objective
I set out with one simple goal: clearly document the differences between
each of the component lifecycle events via module docs.
Unfortunately, no such module existed: the various lifecycle code was
scattered to the wind.
Without a unified module, it's very hard to discover the related types,
and there's nowhere good to put my shiny new documentation.
## Solution
1. Unify the assorted types into a single
`bevy_ecs::component_lifecycle` module.
2. Write docs.
3. Write a migration guide.
## Testing
Thanks CI!
## Follow-up
1. The lifecycle event names are pretty confusing, especially
`OnReplace`. We should consider renaming those. No bikeshedding in my PR
though!
2. Observers need real module docs too :(
3. Any additional functional changes should be done elsewhere; this is a
simple docs and re-org PR.
---------
Co-authored-by: theotherphil <phil.j.ellison@gmail.com>
# Objective
- Cleanup related to #19495.
## Solution
- Delete `System::component_access()`. It is redundant with
`System::component_access_set().combined_access()`.
## Testing
- None. There are no callers of this function.
# Objective
Rename `JustifyText`:
* The name `JustifyText` is just ugly.
* It's inconsistent since no other `bevy_text` types have a `Text-`
suffix, only prefix.
* It's inconsistent with the other text layout enum `Linebreak` which
doesn't have a prefix or suffix.
Fixes#19521.
## Solution
Rename `JustifyText` to `Justify`.
Without other context, it's natural to assume the name `Justify` refers
to text justification.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
`Entity::PLACEHOLDER` acts as a magic number that will *probably* never
really exist, but it certainly could. And, `Entity` has a niche, so the
only reason to use `PLACEHOLDER` is as an alternative to `MaybeUninit`
that trades safety risks for logic risks.
As a result, bevy has generally advised against using `PLACEHOLDER`, but
we still use if for a lot internally. This pr starts removing internal
uses of it, starting from observers.
## Solution
Change all trigger target related types from `Entity` to
`Option<Entity>`
Small migration guide to come.
## Testing
CI
## Future Work
This turned a lot of code from
```rust
trigger.target()
```
to
```rust
trigger.target().unwrap()
```
The extra panic is no worse than before; it's just earlier than
panicking after passing the placeholder to something else.
But this is kinda annoying.
I would like to add a `TriggerMode` or something to `Event` that would
restrict what kinds of targets can be used for that event. Many events
like `Removed` etc, are always triggered with a target. We can make
those have a way to assume Some, etc. But I wanted to save that for a
future pr.
# Objective
Add specialized UI transform `Component`s and fix some related problems:
* Animating UI elements by modifying the `Transform` component of UI
nodes doesn't work very well because `ui_layout_system` overwrites the
translations each frame. The `overflow_debug` example uses a horrible
hack where it copies the transform into the position that'll likely
cause a panic if any users naively copy it.
* Picking ignores rotation and scaling and assumes UI nodes are always
axis aligned.
* The clipping geometry stored in `CalculatedClip` is wrong for rotated
and scaled elements.
* Transform propagation is unnecessary for the UI, the transforms can be
updated during layout updates.
* The UI internals use both object-centered and top-left-corner-based
coordinates systems for UI nodes. Depending on the context you have to
add or subtract the half-size sometimes before transforming between
coordinate spaces. We should just use one system consistantly so that
the transform can always be directly applied.
* `Transform` doesn't support responsive coordinates.
## Solution
* Unrequire `Transform` from `Node`.
* New components `UiTransform`, `UiGlobalTransform`:
- `Node` requires `UiTransform`, `UiTransform` requires
`UiGlobalTransform`
- `UiTransform` is a 2d-only equivalent of `Transform` with a
translation in `Val`s.
- `UiGlobalTransform` newtypes `Affine2` and is updated in
`ui_layout_system`.
* New helper functions on `ComputedNode` for mapping between viewport
and local node space.
* The cursor position is transformed to local node space during picking
so that it respects rotations and scalings.
* To check if the cursor hovers a node recursively walk up the tree to
the root checking if any of the ancestor nodes clip the point at the
cursor. If the point is clipped the interaction is ignored.
* Use object-centered coordinates for UI nodes.
* `RelativeCursorPosition`'s coordinates are now object-centered with
(0,0) at the the center of the node and the corners at (±0.5, ±0.5).
* Replaced the `normalized_visible_node_rect: Rect` field of
`RelativeCursorPosition` with `cursor_over: bool`, which is set to true
when the cursor is over an unclipped point on the node. The visible area
of the node is not necessarily a rectangle, so the previous
implementation didn't work.
This should fix all the logical bugs with non-axis aligned interactions
and clipping. Rendering still needs changes but they are far outside the
scope of this PR.
Tried and abandoned two other approaches:
* New `transform` field on `Node`, require `GlobalTransform` on `Node`,
and unrequire `Transform` on `Node`. Unrequiring `Transform` opts out of
transform propagation so there is then no conflict with updating the
`GlobalTransform` in `ui_layout_system`. This was a nice change in its
simplicity but potentially confusing for users I think, all the
`GlobalTransform` docs mention `Transform` and having special rules for
how it's updated just for the UI is unpleasently surprising.
* New `transform` field on `Node`. Unrequire `Transform` on `Node`. New
`transform: Affine2` field on `ComputedNode`.
This was okay but I think most users want a separate specialized UI
transform components. The fat `ComputedNode` doesn't work well with
change detection.
Fixes#18929, #18930
## Testing
There is an example you can look at:
```
cargo run --example ui_transform
```
Sometimes in the example if you press the rotate button couple of times
the first glyph from the top label disappears , I'm not sure what's
causing it yet but I don't think it's related to this PR.
## Migration Guide
New specialized 2D UI transform components `UiTransform` and
`UiGlobalTransform`. `UiTransform` is a 2d-only equivalent of
`Transform` with a translation in `Val`s. `UiGlobalTransform` newtypes
`Affine2` and is updated in `ui_layout_system`.
`Node` now requires `UiTransform` instead of `Transform`. `UiTransform`
requires `UiGlobalTransform`.
In previous versions of Bevy `ui_layout_system` would overwrite UI
node's `Transform::translation` each frame. `UiTransform`s aren't
overwritten and there is no longer any need for systems that cache and
rewrite the transform for translated UI elements.
`RelativeCursorPosition`'s coordinates are now object-centered with
(0,0) at the the center of the node and the corners at (±0.5, ±0.5). Its
`normalized_visible_node_rect` field has been removed and replaced with
a new `cursor_over: bool` field which is set to true when the cursor is
hovering an unclipped area of the UI node.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- A preparation for the 'system as entities'
- The current system has a series of states such as `is_send`,
`is_exclusive`, `has_defered`, As `system as entites` landed, it may
have more states. Using Bitflags to unify all states is a more concise
and performant approach
## Solution
- Using Bitflags to unify system state.
# Objective
Certain classes of games, usually those with enormous worlds, require
some amount of support for double-precision. Libraries like `big_space`
exist to allow for large worlds while integrating cleanly with Bevy's
primarily single-precision ecosystem, but even then, games will often
still work directly in double-precision throughout the part of the
pipeline that feeds into the Bevy interface.
Currently, working with double-precision types in Bevy is a pain. `glam`
provides types like `DVec3`, but Bevy doesn't provide double-precision
analogs for `glam` wrappers like `Dir3`. This is mostly because doing so
involves one of:
- code duplication
- generics
- templates (like `glam` uses)
- macros
Each of these has issues that are enough to be deal-breakers as far as
maintainability, usability or readability. To work around this, I'm
putting together `bevy_dmath`, a crate that duplicates `bevy_math` types
and functionality to allow downstream users to enjoy the ergonomics and
power of `bevy_math` in double-precision. For the most part, it's a
smooth process, but in order to fully integrate, there are some
necessary changes that can only be made in `bevy_math`.
## Solution
This PR addresses the first and easiest issue with downstream
double-precision math support: `VectorSpace` currently can only
represent vector spaces over `f32`. This automatically closes the door
to double-precision curves, among other things. This restriction can be
easily lifted by allowing vector spaces to specify the underlying scalar
field. This PR adds a new trait `ScalarField` that satisfies the
properties of a scalar field (the ones that can be upheld statically)
and adds a new associated type `type Scalar: ScalarField` to
`VectorSpace`. It's mostly an unintrusive change. The biggest annoyances
are:
- it touches a lot of curve code
- `bevy_math::ops` doesn't support `f64`, so there are some annoying
workarounds
As far as curves code, I wanted to make this change unintrusive and
bite-sized, so I'm trying to touch as little code as possible. To prove
to myself it can be done, I went ahead and (*not* in this PR) migrated
most of the curves API to support different `ScalarField`s and it went
really smoothly! The ugliest thing was adding `P::Scalar: From<usize>`
in several places. There's an argument to be made here that we should be
using `num-traits`, but that's not immediately relevant. The point is
that for now, the smallest change I could make was to go into every
curve impl and make them generic over `VectorSpace<Scalar = f32>`.
Curves work exactly like before and don't change the user API at all.
# Follow-up
- **Extend `bevy_math::ops` to work with `f64`.** `bevy_math::ops` is
used all over, and if curves are ever going to support different
`ScalarField` types, we'll need to be able to use the correct `std` or
`libm` ops for `f64` types as well. Adding an `ops64` mod turned out to
be really ugly, but I'll point out the maintenance burden is low because
we're not going to be adding new floating-point ops anytime soon.
Another solution is to build a floating-point trait that calls the right
op variant and impl it for `f32` and `f64`. This reduces maintenance
burden because on the off chance we ever *do* want to go modify it, it's
all tied together: you can't change the interface on one without
changing the trait, which forces you to update the other. A third option
is to use `num-traits`, which is basically option 2 but someone else did
the work for us. They already support `no_std` using `libm`, so it would
be more or less a drop-in replacement. They're missing a couple
floating-point ops like `floor` and `ceil`, but we could make our own
floating-point traits for those (there's even the potential for
upstreaming them into `num-traits`).
- **Tweak curves to accept vector spaces over any `ScalarField`.**
Curves are ready to support custom scalar types as soon as the bullet
above is addressed. I will admit that the code is not as fun to look at:
`P::Scalar` instead of `f32` everywhere. We could consider an alternate
design where we use `f32` even to interpolate something like a `DVec3`,
but personally I think that's a worse solution than parameterizing
curves over the vector space's scalar type. At the end of the day, it's
not really bad to deal with in my opinion... `ScalarType` supports
enough operations that working with them is almost like working with raw
float types, and it unlocks a whole ecosystem for games that want to use
double-precision.
# Objective
As discussed in #19285, we do a poor job at keeping the namespace tidy
and free of duplicates / user-conflicting names in places. `cosmic_text`
re-exports were the worst offender.
## Solution
Remove the re-exports completely. While the type aliases were quite
thoughtful, they weren't used in any of our code / API.
fix: [Ensure linear volume subtraction does not go below zero
](https://github.com/bevyengine/bevy/issues/19417)
## Solution
- Clamp the result of linear volume subtraction to a minimum of 0.0
- Add a new test case to verify behavior when subtracting beyond zero
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>
# Objective
- `LoadContext::labeled_asset_scope` cannot return errors back to the
asset loader. This means users that need errors need to fall back to
using the raw `begin_labeled_asset` and `add_loaded_labeled_asset`,
which is more error-prone.
## Solution
- Allow returning a (generic) error from `labeled_asset_scope`.
- This has the unfortunate side effect that closures which don't return
any errors need to A) return Ok at the end, B) need to specify an error
type (e.g., `()`).
---
## Showcase
```rust
// impl AssetLoader for MyLoader
let handle = load_context.labeled_asset_scope("MySubasset", |mut load_context| {
if !some_precondition {
return Err(ThingsDontMakeSenseError);
}
let handle = load_context.add_labeled_asset("MySubasset/Other", SomeOtherThing(456));
Ok(Something{ id: 123, handle })
})?;
```
The first 4 commits are designed to be reviewed independently.
- Mark TAA non-experimental now that motion vectors are written for
skinned and morphed meshes, along with skyboxes, and add it to
DefaultPlugins
- Adjust halton sequence to match what DLSS is going to use, doesn't
really affect anything, but may as well
- Make MipBias a required component on TAA instead of inserting it in
the render world
- Remove MipBias, TemporalJitter, RenderLayers, etc from the render
world if they're removed from the main world (fixes a retained render
world bug)
- Remove TAA components from the render world properly if
TemporalAntiAliasing is removed from the main world (fixes a retained
render world bug)
- extract_taa_settings() now has to query over `Option<&mut
TemporalAntiAliasing>`, which will match every single camera, in order
to cover cameras that had TemporalAntiAliasing removed this frame. This
kind of sucks, but I can't think of anything better.
- We probably have the same bug with every other rendering feature
component we have.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
This adds support for clearing events when **entering** a state (instead
of just when exiting) and updates the names to match
`DespawnOnExitState`.
Before:
```rust
app.add_state_scoped_event::<MyGameEvent>(GameState::Play);
```
After:
```rust
app
.add_event::<MyGameEvent>()
.clear_events_on_exit_state::<MyGameEvent>(GameState::Play);
```
# Objective
This is the first step of #19430 and is a follow up for #19132.
Now that `ArchetypeRow` has a niche, we can use `Option` instead of
needing `INVALID` everywhere.
This was especially concerning since `INVALID` *really was valid!*
Using options here made the code clearer and more data-driven.
## Solution
Replace all uses of `INVALID` entity locations (and archetype/table
rows) with `None`.
## Testing
CI
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
#19047 added an `MaybeUninit` field to `EntityMeta`, but did not
guarantee that it will be initialized before access:
```rust
let mut world = World::new();
let id = world.entities().reserve_entity();
world.flush();
world.entity(id);
```
<details>
<summary>Miri Error</summary>
```
error: Undefined Behavior: using uninitialized data, but this operation requires initialized memory
--> /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1121:26
|
1121 | unsafe { meta.spawned_or_despawned.assume_init() }
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ using uninitialized data, but this operation requires initialized memory
|
= help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
= help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
= note: BACKTRACE:
= note: inside closure at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1121:26: 1121:65
= note: inside `std::option::Option::<&bevy_ecs::entity::EntityMeta>::map::<bevy_ecs::entity::SpawnedOrDespawned, {closure@bevy_ecs::entity::Entities::entity_get_spawned_or_despawned::{closure#1}}>` at /home/vj/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:1144:29: 1144:33
= note: inside `bevy_ecs::entity::Entities::entity_get_spawned_or_despawned` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1112:9: 1122:15
= note: inside closure at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1094:13: 1094:57
= note: inside `bevy_ecs::change_detection::MaybeLocation::<std::option::Option<&std::panic::Location<'_>>>::new_with_flattened::<{closure@bevy_ecs::entity::Entities::entity_get_spawned_or_despawned_by::{closure#0}}>` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/change_detection.rs:1371:20: 1371:24
= note: inside `bevy_ecs::entity::Entities::entity_get_spawned_or_despawned_by` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1093:9: 1096:11
= note: inside `bevy_ecs::entity::Entities::entity_does_not_exist_error_details` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1163:23: 1163:70
= note: inside `bevy_ecs::entity::EntityDoesNotExistError::new` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/entity/mod.rs:1182:22: 1182:74
= note: inside `bevy_ecs::world::unsafe_world_cell::UnsafeWorldCell::<'_>::get_entity` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/world/unsafe_world_cell.rs:368:20: 368:73
= note: inside `<bevy_ecs::entity::Entity as bevy_ecs::world::WorldEntityFetch>::fetch_ref` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/world/entity_fetch.rs:207:21: 207:42
= note: inside `bevy_ecs::world::World::get_entity::<bevy_ecs::entity::Entity>` at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/world/mod.rs:911:18: 911:42
note: inside `main`
--> src/main.rs:12:15
|
12 | world.entity(id);
|
```
</details>
## Solution
- remove the existing `MaybeUninit` in `EntityMeta.spawned_or_despawned`
- initialize during flush. This is not needed for soundness, but not
doing this means we can't return a sensible location/tick for flushed
entities.
## Testing
Test via the snippet above (also added equivalent test).
---------
Co-authored-by: urben1680 <55257931+urben1680@users.noreply.github.com>
# Objective
Renames `Timer::finished` and `Timer::paused` to `Timer::is_finished`
and `Timer::is_paused` to align the public APIs for `Time`, `Timer`, and
`Stopwatch`.
Fixes#19110
# Objective
Remove `ArchetypeComponentId` and `archetype_component_access`.
Following #16885, they are no longer used by the engine, so we can stop
spending time calculating them or space storing them.
## Solution
Remove `ArchetypeComponentId` and everything that touches it.
The `System::update_archetype_component_access` method no longer needs
to update `archetype_component_access`. We do still need to update query
caches, but we no longer need to do so *before* running the system. We'd
have to touch every caller anyway if we gave the method a better name,
so just remove `System::update_archetype_component_access` and
`SystemParam::new_archetype` entirely, and update the query cache in
`Query::get_param`.
The `Single` and `Populated` params also need their query caches updated
in `SystemParam::validate_param`, so change `validate_param` to take
`&mut Self::State` instead of `&Self::State`.
# Objective
- move SyncCell and SyncUnsafeCell to bevy_platform
## Solution
- move SyncCell and SyncUnsafeCell to bevy_platform
## Testing
- cargo clippy works
# Objective
- Enable state scoped entities by default
- Provide a way to disable it when needed
---------
Co-authored-by: Ben Frankel <ben.frankel7@gmail.com>
# Objective
- Simplify `Camera` initialization
- allow effects to require HDR
## Solution
- Split out `Camera.hdr` into a marker `Hdr` component
## Testing
- ran `bloom_3d` example
---
## Showcase
```rs
// before
commands.spawn((
Camera3d
Camera {
hdr: true
..Default::default()
}
))
// after
commands.spawn((Camera3d, Hdr));
// other rendering components can require that the camera enables hdr!
// currently implemented for Bloom, AutoExposure, and Atmosphere.
#[require(Hdr)]
pub struct Bloom;
```
## produce a DragEnter event when reentering the dragged entity
when making a piano, i want dragging across the keys to trigger the
notes of each key, but currently if i drag out of a key, then back to
it, this will not work since the dragged entity gets filtered out
## Solution
- make DragEnter event work whenever there's an entry. if the user wants
to ignore the dragged entity they can compare `target` and `dragged`
## Testing
- tested this with a modified version of the 2d_shapes example. i added
an observer to the entities: (and added mesh picking plugin)
```rust
.observe(|t: Trigger<Pointer<DragEnter>>| {
info!("entered {}, started from {}", t.target(), t.dragged);
}
```
- i'm not sure if other things need more testing, or if this is wrong
completely and breaks other things i don't know of!
---
## Showcase
before:
https://github.com/user-attachments/assets/48de606a-e44d-4ca1-ae16-d8dcef640d6e
after:
https://github.com/user-attachments/assets/b1be231f-c826-47bc-be43-c637f22e7846
# Objective
Since #18704 is done, we can track the length of unique entity row
collections with only a `u32` and identify an index within that
collection with only a `NonMaxU32`. This leaves an opportunity for
performance improvements.
## Solution
- Use `EntityRow` in sparse sets.
- Change table, entity, and query lengths to be `u32` instead of
`usize`.
- Keep `batching` module `usize` based since that is reused for events,
which may exceed `u32::MAX`.
- Change according `Range<usize>` to `Range<u32>`. This is more
efficient and helps justify safety.
- Change `ArchetypeRow` and `TableRow` to wrap `NonMaxU32` instead of
`u32`.
Justifying `NonMaxU32::new_unchecked` everywhere is predicated on this
safety comment in `Entities::set`: "`location` must be valid for the
entity at `index` or immediately made valid afterwards before handing
control to unknown code." This ensures no entity is in two table rows
for example. That fact is used to argue uniqueness of the entity rows in
each table, archetype, sparse set, query, etc. So if there's no
duplicates, and a maximum total entities of `u32::MAX` none of the
corresponding row ids / indexes can exceed `NonMaxU32`.
## Testing
CI
---------
Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com>
# Objective
allow specifying the left/top/right/bottom border colors separately for
ui elements
fixes#14773
## Solution
- change `BorderColor` to
```rs
pub struct BorderColor {
pub left: Color,
pub top: Color,
pub right: Color,
pub bottom: Color,
}
```
- generate one ui node per distinct border color, set flags for the
active borders
- render only the active borders
i chose to do this rather than adding multiple colors to the
ExtractedUiNode in order to minimize the impact for the common case
where all border colors are the same.
## Testing
modified the `borders` example to use separate colors:

the behaviour is a bit weird but it mirrors html/css border behaviour.
---
## Migration:
To keep the existing behaviour, just change `BorderColor(color)` into
`BorderColor::all(color)`.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Hiya!
# Objective
- Remove upcasting methods that are no longer necessary since Rust 1.86.
- Cleanup the interned label code.
## Notes
- I didn't try to remove the upcasting methods from `bevy_reflect`, as
there appears to be some complexity related to remote type reflection.
- There are likely some other upcasting methods floating around.
## Testing
I ran the `breakout` example to check that the hashing/eq
implementations of the labels are still correct.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Stores mesh names from glTF files in GltfMeshName component rather than
Name component, making both GltfMeshName and GltfMaterialName behave
like strings via Deref.
# Objective
Fixed the side effects of #19287
Fixes Examples that modify gltf materials are broken #19322
## Solution
Add GltfMeshName component and Deref implementations
Stores mesh names from glTF files in GltfMeshName component rather than
Name component, making both GltfMeshName and GltfMaterialName behave
like strings via Deref.
## Testing
cargo run --example depth_of_field
cargo run --example lightmaps
cargo run --example mixed_lighting
They are consistent with the situation before the error occurred.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Rob Parrett <robparrett@gmail.com>
# Objective
Closes#19175
Make `LogDiagnosticsState` public to be able to edit its filters
## Solution
Make `LogDiagnosticsState` public and add methods to allow editing the
duration and filter
## Testing
`cargo run -p ci`
## Showcase
Updated `log_diagnostics` example

# Objective
Fixes#19120
## Solution
Use the find and replace token feature in VSCode to replace all the
`Condition`s with `SystemCondition`s. Then look through all the
documentation with find and replace to replace all the `Condition`s
there.
## Testing
- Did you test these changes? If so, how?
Yes, used cargo clippy, cargo build and cargo test.
- Are there any parts that need more testing?
Nope
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
By compiling and running bevy
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
Shouldn't be, but Fedora Linux with KDE Wayland
## Objective
Fix the misleading 2d anchor API where `Anchor` is a component and
required by `Text2d` but is stored on a field for sprites.
Fixes#18367
## Solution
Remove the `anchor` field from `Sprite` and require `Anchor` instead.
## Migration Guide
The `anchor` field has been removed from `Sprite`. Instead the `Anchor`
component is now a required component on `Sprite`.
# Objective
[see original
comment](https://github.com/bevyengine/bevy/pull/18801#issuecomment-2796981745)
> Alternately, could we store it on the World instead of a global? I
think we have a World nearby whenever we call default_error_handler().
That would avoid the need for atomics or locks, since we could do
ordinary reads and writes to the World.
Global error handlers don't actually need to be global – per world is
enough. This allows using different handlers for different worlds and
also removes the restrictions on changing the handler only once.
## Solution
Each `World` can now store its own error handler in a resource.
For convenience, you can also set the default error handler for an
`App`, which applies it to the worlds of all `SubApp`s. The old behavior
of only being able to set the error handler once is kept for apps.
We also don't need the `configurable_error_handler` feature anymore now.
## Testing
New/adjusted tests for failing schedule systems & observers.
---
## Showcase
```rust
App::new()
.set_error_handler(info)
…
```
# Objective
This is a followup to #18704 . There's lots more followup work, but this
is the minimum to unblock #18670, etc.
This direction has been given the green light by Alice
[here](https://github.com/bevyengine/bevy/pull/18704#issuecomment-2853368129).
## Solution
I could have split this over multiple PRs, but I figured skipping
straight here would be easiest for everyone and would unblock things the
quickest.
This removes the now no longer needed `identifier` module and makes
`Entity::generation` go from `NonZeroU32` to `struct
EntityGeneration(u32)`.
## Testing
CI
---------
Co-authored-by: Mark Nokalt <marknokalt@live.com>
# Objective
There are two problems this aims to solve.
First, `Entity::index` is currently a `u32`. That means there are
`u32::MAX + 1` possible entities. Not only is that awkward, but it also
make `Entity` allocation more difficult. I discovered this while working
on remote entity reservation, but even on main, `Entities` doesn't
handle the `u32::MAX + 1` entity very well. It can not be batch reserved
because that iterator uses exclusive ranges, which has a maximum upper
bound of `u32::MAX - 1`. In other words, having `u32::MAX` as a valid
index can be thought of as a bug right now. We either need to make that
invalid (this PR), which makes Entity allocation cleaner and makes
remote reservation easier (because the length only needs to be u32
instead of u64, which, in atomics is a big deal), or we need to take
another pass at `Entities` to make it handle the `u32::MAX` index
properly.
Second, `TableRow`, `ArchetypeRow` and `EntityIndex` (a type alias for
u32) all have `u32` as the underlying type. That means using these as
the index type in a `SparseSet` uses 64 bits for the sparse list because
it stores `Option<IndexType>`. By using `NonMaxU32` here, we cut the
memory of that list in half. To my knowledge, `EntityIndex` is the only
thing that would really benefit from this niche. `TableRow` and
`ArchetypeRow` I think are not stored in an `Option` in bulk. But if
they ever are, this would help. Additionally this ensures
`TableRow::INVALID` and `ArchetypeRow::INVALID` never conflict with an
actual row, which in a nice bonus.
As a related note, if we do components as entities where `ComponentId`
becomes `Entity`, the the `SparseSet<ComponentId>` will see a similar
memory improvement too.
## Solution
Create a new type `EntityRow` that wraps `NonMaxU32`, similar to
`TableRow` and `ArchetypeRow`.
Change `Entity::index` to this type.
## Downsides
`NonMax` is implemented as a `NonZero` with a binary inversion. That
means accessing and storing the value takes one more instruction. I
don't think that's a big deal, but it's worth mentioning.
As a consequence, `to_bits` uses `transmute` to skip the inversion which
keeps it a nop. But that also means that ordering has now flipped. In
other words, higher indices are considered less than lower indices. I
don't think that's a problem, but it's also worth mentioning.
## Alternatives
We could keep the index as a u32 type and just document that `u32::MAX`
is invalid, modifying `Entities` to ensure it never gets handed out.
(But that's not enforced by the type system.) We could still take
advantage of the niche here in `ComponentSparseSet`. We'd just need some
unsafe manual conversions, which is probably fine, but opens up the
possibility for correctness problems later.
We could change `Entities` to fully support the `u32::MAX` index. (But
that makes `Entities` more complex and potentially slightly slower.)
## Testing
- CI
- A few tests were changed because they depend on different ordering and
`to_bits` values.
## Future Work
- It might be worth removing the niche on `Entity::generation` since
there is now a different niche.
- We could move `Entity::generation` into it's own type too for clarity.
- We should change `ComponentSparseSet` to take advantage of the new
niche. (This PR doesn't change that yet.)
- Consider removing or updating `Identifier`. This is only used for
`Entity`, so it might be worth combining since `Entity` is now more
unique.
---------
Co-authored-by: atlv <email@atlasdostal.com>
Co-authored-by: Zachary Harrold <zac@harrold.com.au>
# Objective
Provide a generic `impl SystemParam for Option<P>` that uses system
parameter validation. This immediately gives useful impls for params
like `EventReader` and `GizmosState` that are defined in terms of `Res`.
It also allows third-party system parameters to be usable with `Option`,
which was previously impossible due to orphan rules.
Note that this is a behavior change for `Option<Single>`. It currently
fails validation if there are multiple matching entities, but with this
change it will pass validation and produce `None`.
Also provide an impl for `Result<P, SystemParamValidationError>`. This
allows systems to inspect the error if necessary, either for bubbling it
up or for checking the `skipped` flag.
Fixes#12634Fixes#14949
Related to #18516
## Solution
Add generic `SystemParam` impls for `Option` and `Result`, and remove
the impls for specific types.
Update documentation and `fallible_params` example with the new
semantics for `Option<Single>`.
# Objective
Fixes a part of #14274.
Bevy has an incredibly inconsistent naming convention for its system
sets, both internally and across the ecosystem.
<img alt="System sets in Bevy"
src="https://github.com/user-attachments/assets/d16e2027-793f-4ba4-9cc9-e780b14a5a1b"
width="450" />
*Names of public system set types in Bevy*
Most Bevy types use a naming of `FooSystem` or just `Foo`, but there are
also a few `FooSystems` and `FooSet` types. In ecosystem crates on the
other hand, `FooSet` is perhaps the most commonly used name in general.
Conventions being so wildly inconsistent can make it harder for users to
pick names for their own types, to search for system sets on docs.rs, or
to even discern which types *are* system sets.
To reign in the inconsistency a bit and help unify the ecosystem, it
would be good to establish a common recommended naming convention for
system sets in Bevy itself, similar to how plugins are commonly suffixed
with `Plugin` (ex: `TimePlugin`). By adopting a consistent naming
convention in first-party Bevy, we can softly nudge ecosystem crates to
follow suit (for types where it makes sense to do so).
Choosing a naming convention is also relevant now, as the [`bevy_cli`
recently adopted
lints](https://github.com/TheBevyFlock/bevy_cli/pull/345) to enforce
naming for plugins and system sets, and the recommended naming used for
system sets is still a bit open.
## Which Name To Use?
Now the contentious part: what naming convention should we actually
adopt?
This was discussed on the Bevy Discord at the end of last year, starting
[here](<https://discord.com/channels/691052431525675048/692572690833473578/1310659954683936789>).
`FooSet` and `FooSystems` were the clear favorites, with `FooSet` very
narrowly winning an unofficial poll. However, it seems to me like the
consensus was broadly moving towards `FooSystems` at the end and after
the poll, with Cart
([source](https://discord.com/channels/691052431525675048/692572690833473578/1311140204974706708))
and later Alice
([source](https://discord.com/channels/691052431525675048/692572690833473578/1311092530732859533))
and also me being in favor of it.
Let's do a quick pros and cons list! Of course these are just what I
thought of, so take it with a grain of salt.
`FooSet`:
- Pro: Nice and short!
- Pro: Used by many ecosystem crates.
- Pro: The `Set` suffix comes directly from the trait name `SystemSet`.
- Pro: Pairs nicely with existing APIs like `in_set` and
`configure_sets`.
- Con: `Set` by itself doesn't actually indicate that it's related to
systems *at all*, apart from the implemented trait. A set of what?
- Con: Is `FooSet` a set of `Foo`s or a system set related to `Foo`? Ex:
`ContactSet`, `MeshSet`, `EnemySet`...
`FooSystems`:
- Pro: Very clearly indicates that the type represents a collection of
systems. The actual core concept, system(s), is in the name.
- Pro: Parallels nicely with `FooPlugins` for plugin groups.
- Pro: Low risk of conflicts with other names or misunderstandings about
what the type is.
- Pro: In most cases, reads *very* nicely and clearly. Ex:
`PhysicsSystems` and `AnimationSystems` as opposed to `PhysicsSet` and
`AnimationSet`.
- Pro: Easy to search for on docs.rs.
- Con: Usually results in longer names.
- Con: Not yet as widely used.
Really the big problem with `FooSet` is that it doesn't actually
describe what it is. It describes what *kind of thing* it is (a set of
something), but not *what it is a set of*, unless you know the type or
check its docs or implemented traits. `FooSystems` on the other hand is
much more self-descriptive in this regard, at the cost of being a bit
longer to type.
Ultimately, in some ways it comes down to preference and how you think
of system sets. Personally, I was originally in favor of `FooSet`, but
have been increasingly on the side of `FooSystems`, especially after
seeing what the new names would actually look like in Avian and now
Bevy. I prefer it because it usually reads better, is much more clearly
related to groups of systems than `FooSet`, and overall *feels* more
correct and natural to me in the long term.
For these reasons, and because Alice and Cart also seemed to share a
preference for it when it was previously being discussed, I propose that
we adopt a `FooSystems` naming convention where applicable.
## Solution
Rename Bevy's system set types to use a consistent `FooSet` naming where
applicable.
- `AccessibilitySystem` → `AccessibilitySystems`
- `GizmoRenderSystem` → `GizmoRenderSystems`
- `PickSet` → `PickingSystems`
- `RunFixedMainLoopSystem` → `RunFixedMainLoopSystems`
- `TransformSystem` → `TransformSystems`
- `RemoteSet` → `RemoteSystems`
- `RenderSet` → `RenderSystems`
- `SpriteSystem` → `SpriteSystems`
- `StateTransitionSteps` → `StateTransitionSystems`
- `RenderUiSystem` → `RenderUiSystems`
- `UiSystem` → `UiSystems`
- `Animation` → `AnimationSystems`
- `AssetEvents` → `AssetEventSystems`
- `TrackAssets` → `AssetTrackingSystems`
- `UpdateGizmoMeshes` → `GizmoMeshSystems`
- `InputSystem` → `InputSystems`
- `InputFocusSet` → `InputFocusSystems`
- `ExtractMaterialsSet` → `MaterialExtractionSystems`
- `ExtractMeshesSet` → `MeshExtractionSystems`
- `RumbleSystem` → `RumbleSystems`
- `CameraUpdateSystem` → `CameraUpdateSystems`
- `ExtractAssetsSet` → `AssetExtractionSystems`
- `Update2dText` → `Text2dUpdateSystems`
- `TimeSystem` → `TimeSystems`
- `AudioPlaySet` → `AudioPlaybackSystems`
- `SendEvents` → `EventSenderSystems`
- `EventUpdates` → `EventUpdateSystems`
A lot of the names got slightly longer, but they are also a lot more
consistent, and in my opinion the majority of them read much better. For
a few of the names I took the liberty of rewording things a bit;
definitely open to any further naming improvements.
There are still also cases where the `FooSystems` naming doesn't really
make sense, and those I left alone. This primarily includes system sets
like `Interned<dyn SystemSet>`, `EnterSchedules<S>`, `ExitSchedules<S>`,
or `TransitionSchedules<S>`, where the type has some special purpose and
semantics.
## Todo
- [x] Should I keep all the old names as deprecated type aliases? I can
do this, but to avoid wasting work I'd prefer to first reach consensus
on whether these renames are even desired.
- [x] Migration guide
- [x] Release notes
# Objective
- Alternative to and builds on top of #16284.
- Fixes#15849.
## Solution
- Rename component `StateScoped` to `DespawnOnExitState`.
- Rename system `clear_state_scoped_entities` to
`despawn_entities_on_exit_state`.
- Add `DespawnOnEnterState` and `despawn_entities_on_enter_state` which
is the `OnEnter` equivalent.
> [!NOTE]
> Compared to #16284, the main change is that I did the rename in such a
way as to keep the terms `OnExit` and `OnEnter` together. In my own
game, I was adding `VisibleOnEnterState` and `HiddenOnExitState` and
when naming those, I kept the `OnExit` and `OnEnter` together. When I
checked #16284 it stood out to me that the naming was a bit awkward.
Putting the `State` in the middle and breaking up `OnEnter` and `OnExit`
also breaks searching for those terms.
## Open questions
1. Should we split `enable_state_scoped_entities` into two functions,
one for the `OnEnter` and one for the `OnExit`? I personally have zero
need thus far for the `OnEnter` version, so I'd be interested in not
having this enabled unless I ask for it.
2. If yes to 1., should we follow my lead in my `Visibility` state
components (see below) and name these
`app.enable_despawn_entities_on_enter_state()` and
`app.enable_despawn_entities_on_exit_state()`, which IMO says what it
does on the tin?
## Testing
Ran all changed examples.
## Side note: `VisibleOnEnterState` and `HiddenOnExitState`
For reference to anyone else and to help with the open questions, I'm
including the code I wrote for controlling entity visibility when a
state is entered/exited.
<details>
<summary>visibility.rs</summary>
```rust
use bevy_app::prelude::*;
use bevy_ecs::prelude::*;
use bevy_reflect::prelude::*;
use bevy_render::prelude::*;
use bevy_state::{prelude::*, state::StateTransitionSteps};
use tracing::*;
pub trait AppExtStates {
fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self;
fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self;
}
impl AppExtStates for App {
fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self {
self.main_mut()
.enable_visible_entities_on_enter_state::<S>();
self
}
fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self {
self.main_mut().enable_hidden_entities_on_exit_state::<S>();
self
}
}
impl AppExtStates for SubApp {
fn enable_visible_entities_on_enter_state<S: States>(&mut self) -> &mut Self {
if !self
.world()
.contains_resource::<Events<StateTransitionEvent<S>>>()
{
let name = core::any::type_name::<S>();
warn!("Visible entities on enter state are enabled for state `{}`, but the state isn't installed in the app!", name);
}
// We work with [`StateTransition`] in set
// [`StateTransitionSteps::ExitSchedules`] as opposed to [`OnExit`],
// because [`OnExit`] only runs for one specific variant of the state.
self.add_systems(
StateTransition,
update_to_visible_on_enter_state::<S>.in_set(StateTransitionSteps::ExitSchedules),
)
}
fn enable_hidden_entities_on_exit_state<S: States>(&mut self) -> &mut Self {
if !self
.world()
.contains_resource::<Events<StateTransitionEvent<S>>>()
{
let name = core::any::type_name::<S>();
warn!("Hidden entities on exit state are enabled for state `{}`, but the state isn't installed in the app!", name);
}
// We work with [`StateTransition`] in set
// [`StateTransitionSteps::ExitSchedules`] as opposed to [`OnExit`],
// because [`OnExit`] only runs for one specific variant of the state.
self.add_systems(
StateTransition,
update_to_hidden_on_exit_state::<S>.in_set(StateTransitionSteps::ExitSchedules),
)
}
}
#[derive(Clone, Component, Debug, Reflect)]
#[reflect(Component, Debug)]
pub struct VisibleOnEnterState<S: States>(pub S);
#[derive(Clone, Component, Debug, Reflect)]
#[reflect(Component, Debug)]
pub struct HiddenOnExitState<S: States>(pub S);
/// Makes entities marked with [`VisibleOnEnterState<S>`] visible when the state
/// `S` is entered.
pub fn update_to_visible_on_enter_state<S: States>(
mut transitions: EventReader<StateTransitionEvent<S>>,
mut query: Query<(&VisibleOnEnterState<S>, &mut Visibility)>,
) {
// We use the latest event, because state machine internals generate at most
// 1 transition event (per type) each frame. No event means no change
// happened and we skip iterating all entities.
let Some(transition) = transitions.read().last() else {
return;
};
if transition.entered == transition.exited {
return;
}
let Some(entered) = &transition.entered else {
return;
};
for (binding, mut visibility) in query.iter_mut() {
if binding.0 == *entered {
visibility.set_if_neq(Visibility::Visible);
}
}
}
/// Makes entities marked with [`HiddenOnExitState<S>`] invisible when the state
/// `S` is exited.
pub fn update_to_hidden_on_exit_state<S: States>(
mut transitions: EventReader<StateTransitionEvent<S>>,
mut query: Query<(&HiddenOnExitState<S>, &mut Visibility)>,
) {
// We use the latest event, because state machine internals generate at most
// 1 transition event (per type) each frame. No event means no change
// happened and we skip iterating all entities.
let Some(transition) = transitions.read().last() else {
return;
};
if transition.entered == transition.exited {
return;
}
let Some(exited) = &transition.exited else {
return;
};
for (binding, mut visibility) in query.iter_mut() {
if binding.0 == *exited {
visibility.set_if_neq(Visibility::Hidden);
}
}
}
```
</details>
---------
Co-authored-by: Benjamin Brienen <Benjamin.Brienen@outlook.com>
Co-authored-by: Ben Frankel <ben.frankel7@gmail.com>