764be9199c
14 Commits
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38c3423693
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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. |
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e5dc177b4b
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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. |
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33c6f45a35
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Rename some pointer events and components (#19574)
# 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` |
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064e5e48b4
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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. |
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65e289f5bc
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Unify picking backends (#17348)
# Objective Currently, our picking backends are inconsistent: - Mesh picking and sprite picking both have configurable opt in/out behavior. UI picking does not. - Sprite picking uses `SpritePickingCamera` and `Pickable` for control, but mesh picking uses `RayCastPickable`. - `MeshPickingPlugin` is not a part of `DefaultPlugins`. `SpritePickingPlugin` and `UiPickingPlugin` are. ## Solution - Add configurable opt in/out behavior to UI picking (defaults to opt out). - Replace `RayCastPickable` with `MeshPickingCamera` and `Pickable`. - Remove `SpritePickingPlugin` and `UiPickingPlugin` from `DefaultPlugins`. ## Testing Ran some examples. ## Migration Guide `UiPickingPlugin` and `SpritePickingPlugin` are no longer included in `DefaultPlugins`. They must be explicitly added. `RayCastPickable` has been replaced in favor of the `MeshPickingCamera` and `Pickable` components. You should add them to cameras and entities, respectively, if you have `MeshPickingSettings::require_markers` set to `true`. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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02bb151889
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Rename PickingBehavior to Pickable (#17266)
# Objective PR #17225 allowed for sprite picking to be opt-in. After some discussion, it was agreed that `PickingBehavior` should be used to opt-in to sprite picking behavior for entities. This leads to `PickingBehavior` having two purposes: mark an entity for use in a backend, and describe how it should be picked. Discussion led to the name `Pickable`making more sense (also: this is what the component was named before upstreaming). A follow-up pass will be made after this PR to unify backends. ## Solution Replace all instances of `PickingBehavior` and `picking_behavior` with `Pickable` and `pickable`, respectively. ## Testing CI ## Migration Guide Change all instances of `PickingBehavior` to `Pickable`. |
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ad4144ad7a
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Rename Pointer<Down/Up> -> Pointer<Pressed/Released> in bevy_picking. (#16331)
# Objective Fixes #16192 ## Solution I renamed the Pointer<Down/Up> to <Pressed/Released> and then I resolved all the errors. Renamed variables like "is_down" to "is_pressed" to maintain consistency. Modified the docs in places where 'down/up' were used to maintain consistency. ## Testing I haven't tested this in any way beside the checks from rust analyzer and the examples in the examples/ directory. --- ## Migration Guide ### `bevy_picking/src/pointer.rs`: #### `enum PressDirection`: - `PressDirection::Down` changes to `PressDirection::Pressed`. - `PressDirection::Up` changes to `PressDirection::Released`. These changes are also relevant when working with `enum PointerAction` ### `bevy_picking/src/events.rs`: Clicking and pressing Events in events.rs categories change from [Down], [Up], [Click] to [Pressed], [Released], [Click]. - `struct Down` changes to `struct Pressed` - fires when a pointer button is pressed over the 'target' entity. - `struct Up` changes to `struct Released` - fires when a pointer button is released over the 'target' entity. - `struct Click` now fires when a pointer sends a Pressed event followed by a Released event on the same 'target'. - `struct DragStart` now fires when the 'target' entity receives a pointer Pressed event followed by a pointer Move event. - `struct DragEnd` now fires when the 'target' entity is being dragged and receives a pointer Released event. - `PickingEventWriters<'w>::down_events: EventWriter<'w, Pointer<Down>>` changes to `PickingEventWriters<'w>::pressed_events: EventWriter<'w, Pointer<Pressed>>`. - `PickingEventWriters<'w>::up_events changes to PickingEventWriters<'w>::released_events`. --------- Co-authored-by: Harun Ibram <harun.ibram@outlook.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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61b98ec80f
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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` |
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03372e590d
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Picking example touchups (#16129)
# Objective - Cleanup pass to make the examples a bit more succinct, focusing on the topic at hand. - Added drag rotation to make the picking examples more interesting, and to demonstrate a simple use case. |
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54b323ec80
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Mesh picking fixes (#16110)
# Objective - Mesh picking is noisy when a non triangle list is used - Mesh picking runs even when users don't need it - Resolve #16065 ## Solution - Don't add the mesh picking plugin by default - Remove error spam |
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7c593179e3
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Fix bevy_picking plugin suffixes (#16082)
# Objective - `MeshPickingBackend` and `SpritePickingBackend` do not have the `Plugin` suffix - `DefaultPickingPlugins` is masquerading as a `Plugin` when in reality it should be a `PluginGroup` - Fixes #16081. ## Solution - Rename some structures: |Original Name|New Name| |-|-| |`MeshPickingBackend`|`MeshPickingPlugin`| |`MeshPickingBackendSettings`|`MeshPickingSettings`| |`SpritePickingBackend`|`SpritePickingPlugin`| |`UiPickingBackendPlugin`|`UiPickingPlugin`| - Make `DefaultPickingPlugins` a `PluginGroup`. - Because `DefaultPickingPlugins` is within the `DefaultPlugins` plugin group, I also added support for nested plugin groups to the `plugin_group!` macro. ## Testing - I used ripgrep to ensure all references were properly renamed. - For the `plugin_group!` macro, I used `cargo expand` to manually inspect the expansion of `DefaultPlugins`. --- ## Migration Guide > [!NOTE] > > All 3 of the changed structures were added after 0.14, so this does not need to be included in the 0.14 to 0.15 migration guide. - `MeshPickingBackend` is now named `MeshPickingPlugin`. - `MeshPickingBackendSettings` is now named `MeshPickingSettings`. - `SpritePickingBackend` is now named `SpritePickingPlugin`. - `UiPickingBackendPlugin` is now named `UiPickingPlugin`. - `DefaultPickingPlugins` is now a a `PluginGroup` instead of a `Plugin`. |
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015f2c69ca
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Merge Style properties into Node. Use ComputedNode for computed properties. (#15975)
# Objective Continue improving the user experience of our UI Node API in the direction specified by [Bevy's Next Generation Scene / UI System](https://github.com/bevyengine/bevy/discussions/14437) ## Solution As specified in the document above, merge `Style` fields into `Node`, and move "computed Node fields" into `ComputedNode` (I chose this name over something like `ComputedNodeLayout` because it currently contains more than just layout info. If we want to break this up / rename these concepts, lets do that in a separate PR). `Style` has been removed. This accomplishes a number of goals: ## Ergonomics wins Specifying both `Node` and `Style` is now no longer required for non-default styles Before: ```rust commands.spawn(( Node::default(), Style { width: Val::Px(100.), ..default() }, )); ``` After: ```rust commands.spawn(Node { width: Val::Px(100.), ..default() }); ``` ## Conceptual clarity `Style` was never a comprehensive "style sheet". It only defined "core" style properties that all `Nodes` shared. Any "styled property" that couldn't fit that mold had to be in a separate component. A "real" style system would style properties _across_ components (`Node`, `Button`, etc). We have plans to build a true style system (see the doc linked above). By moving the `Style` fields to `Node`, we fully embrace `Node` as the driving concept and remove the "style system" confusion. ## Next Steps * Consider identifying and splitting out "style properties that aren't core to Node". This should not happen for Bevy 0.15. --- ## Migration Guide Move any fields set on `Style` into `Node` and replace all `Style` component usage with `Node`. Before: ```rust commands.spawn(( Node::default(), Style { width: Val::Px(100.), ..default() }, )); ``` After: ```rust commands.spawn(Node { width: Val::Px(100.), ..default() }); ``` For any usage of the "computed node properties" that used to live on `Node`, use `ComputedNode` instead: Before: ```rust fn system(nodes: Query<&Node>) { for node in &nodes { let computed_size = node.size(); } } ``` After: ```rust fn system(computed_nodes: Query<&ComputedNode>) { for computed_node in &computed_nodes { let computed_size = computed_node.size(); } } ``` |
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7482a0d26d
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aligning public apis of Time,Timer and Stopwatch (#15962)
Fixes #15834 ## Migration Guide The APIs of `Time`, `Timer` and `Stopwatch` have been cleaned up for consistency with each other and the standard library's `Duration` type. The following methods have been renamed: - `Stowatch::paused` -> `Stopwatch::is_paused` - `Time::elapsed_seconds` -> `Time::elasped_secs` (including `_f64` and `_wrapped` variants) |
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0e30b68b20
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Add mesh picking backend and MeshRayCast system parameter (#15800)
# Objective Closes #15545. `bevy_picking` supports UI and sprite picking, but not mesh picking. Being able to pick meshes would be extremely useful for various games, tools, and our own examples, as well as scene editors and inspectors. So, we need a mesh picking backend! Luckily, [`bevy_mod_picking`](https://github.com/aevyrie/bevy_mod_picking) (which `bevy_picking` is based on) by @aevyrie already has a [backend for it]( |