Commit Graph

18 Commits

Author SHA1 Message Date
Joona Aalto
38c3423693
Event Split: Event, EntityEvent, and BufferedEvent (#19647)
# 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.
2025-06-15 16:46:34 +00:00
Joona Aalto
e5dc177b4b
Rename Trigger to On (#19596)
# 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.
2025-06-12 18:22:33 +00:00
Alice Cecile
6ddd0f16a8
Component lifecycle reorganization and documentation (#19543)
# 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>
2025-06-10 00:59:16 +00:00
Eagster
064e5e48b4
Remove entity placeholder from observers (#19440)
# 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.
2025-06-09 19:37:56 +00:00
UkoeHB
8f3e45b45f
Expose CustomCursorUrl (#19006)
# Objective

`CustomCursorUrl` is inaccessible.

## Solution

Expose `CustomCursorUrl`.
2025-05-06 05:23:48 +00:00
Carter Anderson
e9a0ef49f9
Rename bevy_platform_support to bevy_platform (#18813)
# Objective

The goal of `bevy_platform_support` is to provide a set of platform
agnostic APIs, alongside platform-specific functionality. This is a high
traffic crate (providing things like HashMap and Instant). Especially in
light of https://github.com/bevyengine/bevy/discussions/18799, it
deserves a friendlier / shorter name.

Given that it hasn't had a full release yet, getting this change in
before Bevy 0.16 makes sense.

## Solution

- Rename `bevy_platform_support` to `bevy_platform`.
2025-04-11 23:13:28 +00:00
Gino Valente
9b32e09551
bevy_reflect: Add clone registrations project-wide (#18307)
# Objective

Now that #13432 has been merged, it's important we update our reflected
types to properly opt into this feature. If we do not, then this could
cause issues for users downstream who want to make use of
reflection-based cloning.

## Solution

This PR is broken into 4 commits:

1. Add `#[reflect(Clone)]` on all types marked `#[reflect(opaque)]` that
are also `Clone`. This is mandatory as these types would otherwise cause
the cloning operation to fail for any type that contains it at any
depth.
2. Update the reflection example to suggest adding `#[reflect(Clone)]`
on opaque types.
3. Add `#[reflect(clone)]` attributes on all fields marked
`#[reflect(ignore)]` that are also `Clone`. This prevents the ignored
field from causing the cloning operation to fail.
   
Note that some of the types that contain these fields are also `Clone`,
and thus can be marked `#[reflect(Clone)]`. This makes the
`#[reflect(clone)]` attribute redundant. However, I think it's safer to
keep it marked in the case that the `Clone` impl/derive is ever removed.
I'm open to removing them, though, if people disagree.
4. Finally, I added `#[reflect(Clone)]` on all types that are also
`Clone`. While not strictly necessary, it enables us to reduce the
generated output since we can just call `Clone::clone` directly instead
of calling `PartialReflect::reflect_clone` on each variant/field. It
also means we benefit from any optimizations or customizations made in
the `Clone` impl, including directly dereferencing `Copy` values and
increasing reference counters.

Along with that change I also took the liberty of adding any missing
registrations that I saw could be applied to the type as well, such as
`Default`, `PartialEq`, and `Hash`. There were hundreds of these to
edit, though, so it's possible I missed quite a few.

That last commit is **_massive_**. There were nearly 700 types to
update. So it's recommended to review the first three before moving onto
that last one.

Additionally, I can break the last commit off into its own PR or into
smaller PRs, but I figured this would be the easiest way of doing it
(and in a timely manner since I unfortunately don't have as much time as
I used to for code contributions).

## Testing

You can test locally with a `cargo check`:

```
cargo check --workspace --all-features
```
2025-03-17 18:32:35 +00:00
mgi388
e8cd12daf4
Automatically transform cursor hotspot user asks to flip cursor image (#17540)
# Objective

- As discussed in
https://github.com/bevyengine/bevy/issues/17276#issuecomment-2611203714,
we should transform the cursor's hotspot if the user is asking for the
image to be flipped.
- This becomes more important when a `scale` transform option exists.
It's harder for users to transform the hotspot themselves when using
`scale` because they'd need to look up the image to get its dimensions.
Instead, we let Bevy handle the hotspot transforms and make the
`hotspot` field the "original/source" hotspot.
- Refs #17276.

## Solution

- When the image needs to be transformed, also transform the hotspot. If
the image does not need to be transformed (i.e. fast path), no hotspot
transformation is applied.

## Testing

- Ran the example: `cargo run --example custom_cursor_image
--features=custom_cursor`.
- Add unit tests for the hotspot transform function.
- I also ran the example I have in my `bevy_cursor_kit` crate, which I
think is a good illustration of the reason for this PR.
- In the following videos, there is an arrow pointing up. The button
hover event fires as I move the mouse over it.
- When I press `Y`, the cursor flips. 
- In the first video, on `bevy@main` **before** this PR, notice how the
hotspot is wrong after flipping and no longer hovering the button. The
arrow head and hotspot are no longer synced.
- In the second video, on the branch of **this** PR, notice how the
hotspot gets flipped as soon as I press `Y` and the cursor arrow head is
in the correct position on the screen and still hovering the button.
Speaking back to the objective listed at the start: The user originally
defined the _source_ hotspot for the arrow. Later, they decide they want
to flip the cursor vertically: It's nice that Bevy can automatically
flip the _source_ hotspot for them at the same time it flips the
_source_ image.

First video (main):


https://github.com/user-attachments/assets/1955048c-2f85-4951-bfd6-f0e7cfef0cf8

Second video (this PR):


https://github.com/user-attachments/assets/73cb9095-ecb5-4bfd-af5b-9f772e92bd16
2025-01-28 05:49:46 +00:00
mgi388
14ad25227b
Make CustomCursor variants CustomCursorImage/CustomCursorUrl structs (#17518)
# Objective

- Make `CustomCursor::Image` easier to work with by splitting the enum
variants off into `CustomCursorImage` and `CustomCursorUrl` structs and
deriving `Default` on those structs.
- Refs #17276.

## Testing

- Ran two examples: `cargo run --example custom_cursor_image
--features=custom_cursor` and `cargo run --example window_settings
--features=custom_cursor`
- CI.

---

## Migration Guide

The `CustomCursor` enum's variants now hold instances of
`CustomCursorImage` or `CustomCursorUrl`. Update your uses of
`CustomCursor` accordingly.
2025-01-24 05:39:04 +00:00
Zachary Harrold
9bc0ae33c3
Move hashbrown and foldhash out of bevy_utils (#17460)
# Objective

- Contributes to #16877

## Solution

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

## Testing

- CI

---

## Migration Guide

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

## Notes

- I left `PreHashMap`, `PreHashMapExt`, and `TypeIdMap` in `bevy_utils`
as they might be candidates for micro-crating. They can always be moved
into `bevy_platform_support` at a later date if desired.
2025-01-23 16:46:08 +00:00
mgi388
4d4253430c
Move CustomCursor to bevy_winit/src/custom_cursor.rs (#17381)
# Objective

- Follow up work from
https://github.com/bevyengine/bevy/pull/17121#issuecomment-2576615700 to
keep the `cursor.rs` file more manageable.

## Solution

- Move `CustomCursor` and make it compile.

## Testing

- Ran the example: `cargo run --example custom_cursor_image
--features=custom_cursor`
- CI
2025-01-15 05:35:57 +00:00
mgi388
0756a19f28
Support texture atlases in CustomCursor::Image (#17121)
# Objective

- Bevy 0.15 added support for custom cursor images in
https://github.com/bevyengine/bevy/pull/14284.
- However, to do animated cursors using the initial support shipped in
0.15 means you'd have to animate the `Handle<Image>`: You can't use a
`TextureAtlas` like you can with sprites and UI images.
- For my use case, my cursors are spritesheets. To animate them, I'd
have to break them down into multiple `Image` assets, but that seems
less than ideal.


## Solution

- Allow users to specify a `TextureAtlas` field when creating a custom
cursor image.
- To create parity with Bevy's `TextureAtlas` support on `Sprite`s and
`ImageNode`s, this also allows users to specify `rect`, `flip_x` and
`flip_y`. In fact, for my own use case, I need to `flip_y`.

## Testing

- I added unit tests for `calculate_effective_rect` and
`extract_and_transform_rgba_pixels`.
- I added a brand new example for custom cursor images. It has controls
to toggle fields on and off. I opted to add a new example because the
existing cursor example (`window_settings`) would be far too messy for
showcasing these custom cursor features (I did start down that path but
decided to stop and make a brand new example).
- The new example uses a [Kenny cursor icon] sprite sheet. I included
the licence even though it's not required (and it's CC0).
- I decided to make the example just loop through all cursor icons for
its animation even though it's not a _realistic_ in-game animation
sequence.
- I ran the PNG through https://tinypng.com. Looks like it's about 35KB.
- I'm open to adjusting the example spritesheet if required, but if it's
fine as is, great.

[Kenny cursor icon]: https://kenney-assets.itch.io/crosshair-pack

---

## Showcase


https://github.com/user-attachments/assets/8f6be8d7-d1d4-42f9-b769-ef8532367749

## Migration Guide

The `CustomCursor::Image` enum variant has some new fields. Update your
code to set them.

Before:

```rust
CustomCursor::Image {
    handle: asset_server.load("branding/icon.png"),
    hotspot: (128, 128),
}
```

After:

```rust
CustomCursor::Image {
    handle: asset_server.load("branding/icon.png"),
    texture_atlas: None,
    flip_x: false,
    flip_y: false,
    rect: None,
    hotspot: (128, 128),
}
```

## References

- Feature request [originally raised in Discord].

[originally raised in Discord]:
https://discord.com/channels/691052431525675048/692572690833473578/1319836362219847681
2025-01-14 22:27:24 +00:00
Zachary Harrold
a371ee3019
Remove tracing re-export from bevy_utils (#17161)
# Objective

- Contributes to #11478

## Solution

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

## Testing

- CI

---

## Migration Guide

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

## Notes

- While this doesn't reduce the line-count in `bevy_utils`, it further
decouples the internal crates from `bevy_utils`, making its eventual
removal more feasible in the future.
- I have just imported `tracing` as we do for all dependencies. However,
a workspace dependency may be more appropriate for version management.
2025-01-05 23:06:34 +00:00
Aevyrie
61b98ec80f
Rename trigger.entity() to trigger.target() (#16716)
# Objective

- A `Trigger` has multiple associated `Entity`s - the entity observing
the event, and the entity that was targeted by the event.
- The field `entity: Entity` encodes no semantic information about what
the entity is used for, you can already tell that it's an `Entity` by
the type signature!

## Solution

- Rename `trigger.entity()` to `trigger.target()`

---

## Changelog

- `Trigger`s are associated with multiple entities. `Trigger::entity()`
has been renamed to `Trigger::target()` to reflect the semantics of the
entity being returned.

## Migration Guide

- Rename `Trigger::entity()` to `Trigger::target()`.
- Rename `ObserverTrigger::entity` to `ObserverTrigger::target`
2024-12-08 21:55:09 +00:00
François Mockers
eb558bbf77
properly flag using CustomCursor::Url in wasm (#16255)
# Objective

- Fixes #16254 
- fix building in wasm without custom_cursor

## Solution

- Properly flag `CustomCursor::Url` which only exist in wasm, but also
only when `custom_cursor` is enabled

## Testing

- `cargo check --target wasm32-unknown-unknown -p bevy_winit`
2024-11-06 13:14:12 +00:00
Friz64
565616622b
Correctly feature gate custom_cursor (#16093)
# Objective

Currently there's no way to change the window's cursor icon with the
`custom_cursor` feature **disabled**. You should still be able to set
system cursor icons.

Connections:

- https://github.com/bevyengine/bevy/pull/15649

## Solution

Move some `custom_cursor` feature gates around, as to expose the
`CursorIcon` type again.

Note this refactoring was mainly piloted by hunting after the compiler
warnings -- I shouldn't have missed anything, but FYI.

## Testing

Disabled the `custom_cursor` feature, ran the `window_settings` example.
2024-11-02 01:47:32 +00:00
Christian Hughes
219b5930f1
Rename App/World::observe to add_observer, EntityWorldMut::observe_entity to observe. (#15754)
# Objective

- Closes #15752

Calling the functions `App::observe` and `World::observe` doesn't make
sense because you're not "observing" the `App` or `World`, you're adding
an observer that listens for an event that occurs *within* the `World`.
We should rename them to better fit this.

## Solution

Renames:
- `App::observe` -> `App::add_observer`
- `World::observe` -> `World::add_observer`
- `Commands::observe` -> `Commands::add_observer`
- `EntityWorldMut::observe_entity` -> `EntityWorldMut::observe`

(Note this isn't a breaking change as the original rename was introduced
earlier this cycle.)

## Testing

Reusing current tests.
2024-10-09 15:39:29 +00:00
Bude
6edb78a8c3
Inverse bevy_render bevy_winit dependency and move cursor to bevy_winit (#15649)
# Objective

- `bevy_render` should not depend on `bevy_winit`
- Fixes #15565

## Solution

- `bevy_render` no longer depends on `bevy_winit`
- The following is behind the `custom_cursor` feature
- Move custom cursor code from `bevy_render` to `bevy_winit` behind the
`custom_cursor` feature
- `bevy_winit` now depends on `bevy_render` (for `Image` and
`TextureFormat`)
- `bevy_winit` now depends on `bevy_asset` (for `Assets`, `Handle` and
`AssetId`)
  - `bevy_winit` now depends on `bytemuck` (already in tree)
- Custom cursor code in `bevy_winit` reworked to use `AssetId` (other
than that it is taken over 1:1)
- Rework `bevy_winit` custom cursor interface visibility now that the
logic is all contained in `bevy_winit`

## Testing

- I ran the screenshot and window_settings examples
- Tested on linux wayland so far

---

## Migration Guide

`CursorIcon` and `CustomCursor` previously provided by
`bevy::render::view::cursor` is now available from `bevy::winit`.
A new feature `custom_cursor` enables this functionality (default
feature).
2024-10-06 18:25:50 +00:00