# 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
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
Fixes#19385
Note: this has shader errors due to #19383 and should probably be merged
after #19384
## Solution
- Move the example to the UI testbed
- Adjust label contents and cell size so that every test case fits on
the screen
- Minor tidying, slightly less harsh colors while preserving the
intentional debug coloring
## Testing
`cargo run --example testbed_ui`

---------
Co-authored-by: François Mockers <mockersf@gmail.com>
# 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;
```
# 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>
## 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
Allowing drawing of UI nodes with a gradient instead of a flat color.
## Solution
The are three gradient structs corresponding to the three types of
gradients supported: `LinearGradient`, `ConicGradient` and
`RadialGradient`. These are then wrapped in a `Gradient` enum
discriminator which has `Linear`, `Conic` and `Radial` variants.
Each gradient type consists of the geometric properties for that
gradient and a list of color stops.
Color stops consist of a color, a position or angle and an optional
hint. If no position is specified for a stop, it's evenly spaced between
the previous and following stops. Color stop positions are absolute, if
you specify a list of stops:
```vec


Conic gradients can be used to draw simple pie charts like in CSS:

# 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>
# 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`.
# Objective
Add sprite flipping to `testbed_2d`'s sprite scene
## Solution
Draw the sprite flipped in each axis and both axes.
Changed the sprite to the rectangular bevy banner with text and made the
images different colors.
## Testing
```
cargo run --example testbed_2d
```

---------
Co-authored-by: François Mockers <mockersf@gmail.com>
# Objective
Contributes to #18238
Updates the `shader_prepass`, `testbed_2d` and `first_person_view_model`
examples to use the `children!` macro. I wanted to keep the PR small but
chose to do 3 examples since they were all limited in scope
## Solution
Updates examples to use the Improved Spawning API merged in
https://github.com/bevyengine/bevy/pull/17521
## Testing
- Did you test these changes? If so, how?
- Opened the examples before and after and verified the same behavior
was observed. I did this on Ubuntu 24.04.2 LTS using `--features
wayland`.
- Are there any parts that need more testing?
- Other OS's and features can't hurt, but this is such a small change it
shouldn't be a problem.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Run the examples yourself with and without these changes.
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
- see above
---
## Showcase
n/a
## Migration Guide
n/a
# Objective
The `Anchor` component doesn't need to be a enum. The variants are just
mapped to `Vec2`s so it could be changed to a newtype with associated
const values, saving the space needed for the discriminator by the enum.
Also there was no benefit I think in hiding the underlying `Vec2`
representation of `Anchor`s.
Suggested by @atlv24.
Fixes#18459Fixes#18460
## Solution
Change `Anchor` to a struct newtyping a `Vec2`, and its variants into
associated constants.
## Migration Guide
The anchor component has been changed from an enum to a struct newtyping
a `Vec2`. The `Custom` variant has been removed, instead to construct a
custom `Anchor` use its tuple constructor:
```rust
Sprite {
anchor: Anchor(Vec2::new(0.25, 0.4)),
..default()
}
```
The other enum variants have been replaced with corresponding constants:
* `Anchor::BottomLeft` to `Anchor::BOTTOM_LEFT`
* `Anchor::Center` to `Anchor::CENTER`
* `Anchor::TopRight` to `Anchor::TOP_RIGHT`
* .. and so on for the remaining variants
# Objective
Contributes to #18238
Updates the `text2d`, example to use the `children!` macro.
~~The SpawnIter usage in this example is maybe not the best. Very open
to opinions. I even left one `with_children` that I thought was just
much better than any alternative.~~
## Solution
Updates examples to use the Improved Spawning API merged in
https://github.com/bevyengine/bevy/pull/17521
## Testing
- Did you test these changes? If so, how?
- Opened the examples before and after and verified the same behavior
was observed. I did this on Ubuntu 24.04.2 LTS using `--features
wayland`.
- Are there any parts that need more testing?
- Other OS's and features can't hurt, but this is such a small change it
shouldn't be a problem.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- Run the examples yourself with and without these changes.
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
- see above
---
## Showcase
n/a
## Migration Guide
n/a
# Objective
- #17581 broke gizmos
- Fixes#18325
## Solution
- Revert #17581
- Add gizmos to testbed
## Testing
- Run any example with gizmos, it renders correctly
# Objective
`Text2d` testing hasn't been as thorough as text in the UI, and it
suffered a bunch of bugs / perf issues in recent cycles.
## Solution
Add some more `Text2d` scenarios to the 2d testbed to catch bugs,
testing bounded and unbounded text with various justification.
## Testing
`cargo run --example testbed_2d` (press space a few times)
<img width="1280" alt="Screenshot 2025-03-10 at 1 02 03 PM"
src="https://github.com/user-attachments/assets/1e4ee39c-809b-4cc6-81bd-68e67b9625b5"
/>
---------
Co-authored-by: Ben Frankel <ben.frankel7@gmail.com>
# Objective
- have a testbed for UI
## Solution
- move previous `ui` example to `full_ui`
- add a testbed ui with several scenes
- `ui_layout_rounding` is one of those scenes, so remove it as a
standalone example
the previous `ui` / new `full_ui` is I think still useful as it has some
things like scroll, debug ui that are not shown anywhere else
# Objective
Fix gltf validation errors in `Fox.glb`.
Inspired by #8099, but that issue doesn't appear to describe a real bug
to fix, as far as I can tell.
## Solution
Use the latest version of the Fox from
[glTF-Sample-Assets](https://github.com/KhronosGroup/glTF-Sample-Assets/blob/main/Models/Fox/glTF-Binary/Fox.glb).
## Testing
Dropped both versions in https://github.khronos.org/glTF-Validator/
`cargo run --example animated_mesh` seems to still look fine.
Before:
```
The asset contains errors.
"numErrors": 126,
"numWarnings": 4184,
```
After:
```
The asset is valid.
"numErrors": 0,
"numWarnings": 0,
```
## Discussion
The 3d testbed was panicking with
```
thread 'main' panicked at examples/testbed/3d.rs:288:60:
called `Result::unwrap()` on an `Err` value: QueryDoesNotMatch(35v1 with components Transform, GlobalTransform, Visibility, InheritedVisibility, ViewVisibility, ChildOf, Children, Name)
```
Which is bizarre. I think this might be related to #17720, or maybe the
structure of the gltf changed.
I fixed it by using updating the testbed to use a more robust method of
finding the correct entity as is done in `animated_mesh`.
# Objective
- Improve CI when testing rendering by having smarter testbeds
## Solution
- CI testing no longer need a config file and will run with a default
config if not found
- It is now possible to give a name to a screenshot instead of just a
frame number
- 2d and 3d testbeds are now driven from code
- a new system in testbed will watch for state changed
- on state changed, trigger a screenshot 100 frames after (so that the
scene has time to render) with the name of the scene
- when the screenshot is taken (`Captured` component has been removed),
switch scene
- this means less setup to run a testbed (no need for a config file),
screenshots have better names, and it's faster as we don't wait 100
frames for the screenshot to be taken
## Testing
- `cargo run --example testbed_2d --features bevy_ci_testing`
Fixes#17412
## Objective
`Parent` uses the "has a X" naming convention. There is increasing
sentiment that we should use the "is a X" naming convention for
relationships (following #17398). This leaves `Children` as-is because
there is prevailing sentiment that `Children` is clearer than `ParentOf`
in many cases (especially when treating it like a collection).
This renames `Parent` to `ChildOf`.
This is just the implementation PR. To discuss the path forward, do so
in #17412.
## Migration Guide
- The `Parent` component has been renamed to `ChildOf`.
# 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`.
# Objective
The UI debug overlay draws an outline for every UI node even if it is
invisible or clipped.
Disable debug outlines for hidden and clipped nodes by default and add
options to renable them if needed.
## Solution
* Add `show_hidden` and `show_clipped` fields to `UiDebugOptions`:
```rust
/// Show outlines for non-visible UI nodes
pub show_hidden: bool,
/// Show outlines for clipped sections of UI nodes
pub show_clipped: bool,
```
* Only extract debug outlines for hidden and clipped UI nodes if the
respective field in `UiDebugOptions` is set to `true`.
## Testing
Also added some extra features to the `testbed_ui` example that
demonstrate the new options:
cargo run --example testbed_ui --features "bevy_ui_debug"
<img width="641" alt="show-hidden-and-clipped"
src="https://github.com/user-attachments/assets/16a68600-170c-469e-a3c7-f7dae411dc40"
/>
# Objective
With the introduction of bevy_input_focus, the uses of "focus" in
bevy_picking are quite confusing and make searching hard.
Users will intuitively think these concepts are related, but they
actually aren't.
## Solution
Rename / rephrase all uses of "focus" in bevy_picking to refer to
"hover", since this is ultimately related to creating the `HoverMap`.
## Migration Guide
Various terms related to "focus" in `bevy_picking` have been renamed to
refer to "hover" to avoid confusion with `bevy_input_focus`. In
particular:
- The `update_focus` system has been renamed to `generate_hovermap`
- `PickSet::Focus` and `PostFocus` have been renamed to `Hover` and
`PostHover`
- The `bevy_picking::focus` module has been renamed to
`bevy_picking::hover`
- The `is_focus_enabled` field on `PickingPlugin` has been renamed to
`is_hover_enabled`
- The `focus_should_run` run condition has been renamed to
`hover_should_run`
# Objective
Rust-Analyzer was reporting problems with dead code in the 3d testbed
scene.
## Solution
These scenes don't work in CI on the Windows runner (because they're too
weak).
Mirror the feature flags from above onto the offending modules.
## Testing
RA no longer complains.
# Objective
Draw the UI debug overlay using the UI renderer.
Significantly simpler and easier to use than
`bevy_dev_tools::ui_debug_overlay` which uses `bevy_gizmos`.
* Supports multiple windows and UI rendered to texture.
* Draws rounded debug rects for rounded UI nodes.
Fixes#16666
## Solution
Removed the `ui_debug_overlay` module from `bevy_dev_tools`.
Added a `bevy_ui_debug` feature gate.
Draw the UI debug overlay using the UI renderer.
Adds a new module `bevy_ui::render::debug_overlay`.
The debug overlay extraction function queries for the existing UI layout
and then adds a border around each UI node with `u32::MAX / 2` added to
each stack index so it's drawn on top.
There is a `UiDebugOptions` resource that can be used to enable or
disable the debug overlay and set the line width.
## Testing
The `testbed_ui` example has been changed to use the new debug overlay:
```
cargo run --example testbed_ui --features bevy_ui_debug
```
Press Space to toggle the debug overlay on and off.
---
## Showcase
<img width="961" alt="testbed-ui-new-debug"
src="https://github.com/user-attachments/assets/e9523d18-39ae-46a8-adbe-7d3f3ab8e951">
## Migration Guide
The `ui_debug_overlay` module has been removed from `bevy_dev_tools`.
There is a new debug overlay implemented using the `bevy_ui` renderer.
To use it, enable the `bevy_ui_debug` feature and set the `enable` field
of the `UiDebugOptions` resource to `true`.
# 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`
# Objective
The `UiBoxShadowSamples` resource should be renamed to
`BoxShadowSamples` so it matches the `BoxShadow` component.
## Migration Guide
`UiBoxShadowSamples` has been renamed to `BoxShadowSamples`
# Objective
Add support for multiple box shadows on a single `Node`.
## Solution
* Rename `BoxShadow` to `ShadowStyle` and remove its `Component` derive.
* Create a new `BoxShadow` component that newtypes a `Vec<ShadowStyle>`.
* Add a `new` constructor method to `BoxShadow` for single shadows.
* Change `extract_shadows` to iterate through a list of shadows per
node.
Render order is determined implicitly from the order of the shadows
stored in the `BoxShadow` component, back-to-front.
Might be more efficient to use a `SmallVec<[ShadowStyle; 1]>` for the
list of shadows but not sure if the extra friction is worth it.
## Testing
Added a node with four differently coloured shadows to the `box_shadow`
example.
---
## Showcase
```
cargo run --example box_shadow
```
<img width="460" alt="four-shadow"
src="https://github.com/user-attachments/assets/2f728c47-33b4-42e1-96ba-28a774b94b24">
## Migration Guide
Bevy UI now supports multiple shadows per node. A new struct
`ShadowStyle` is used to set the style for each shadow. And the
`BoxShadow` component is changed to a tuple struct wrapping a vector
containing a list of `ShadowStyle`s. To spawn a node with a single
shadow you can use the `new` constructor function:
```rust
commands.spawn((
Node::default(),
BoxShadow::new(
Color::BLACK.with_alpha(0.8),
Val::Percent(offset.x),
Val::Percent(offset.y),
Val::Percent(spread),
Val::Px(blur),
)
));
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I got tired of calling `enable_state_scoped_entities`, and though it
would make more sense to define that at the place where the state is
defined
## Solution
- add a derive attribute `#[states(scoped_entities)]` when derive
`States` or `SubStates` that enables it automatically when adding the
state
## Testing
- Ran the examples using it, they still work
# Objective
Run `testbed_ui` example:
```
cargo run --example testbed_ui
```
The scroll list is non-scrollable because it's blocked by the front
four-icon node.
## Solution
Add `PickingBehavior::IGNORE` for the front node
## Testing
- Did you test these changes? If so, how?
Yes.
- Are there any parts that need more testing?
No, I guess.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
```
cargo run --example testbed_ui
```
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
macOS.
# Objective
- Progress towards #15918
- Add test on UI
## Solution
- Get a single screenshot from the UI testbed example
- Remove older examples from runs in CI as they're covered by the
testbed to reduce CI duration
# Objective
UI Anti-aliasing is incorrectly implemented. It always uses an edge
radius of 0.25 logical pixels, and ignores the physical resolution. For
low dpi screens 0.25 is is too low and on higher dpi screens the
physical edge radius is much too large, resulting in visual artifacts.
## Solution
Multiply the distance by the scale factor in the `antialias` function so
that the edge radius stays constant in physical pixels.
## Testing
To see the problem really clearly run the button example with `UiScale`
set really high. With `UiScale(25.)` on main if you examine the button's
border you can see a thick gradient fading away from the edges:
<img width="127" alt="edgg"
src="https://github.com/user-attachments/assets/7c852030-c0e8-4aef-8d3e-768cb2464cab">
With this PR the edges are sharp and smooth at all scale factors:
<img width="127" alt="edge"
src="https://github.com/user-attachments/assets/b3231140-1bbc-4a4f-a1d3-dde21f287988">
# Objective
- Fixes#16235
## Solution
- Both Bevy and AccessKit export a `Node` struct, to reduce confusion
Bevy will no longer re-export `AccessKit` from `bevy_a11y`
## Testing
- Tested locally
## Migration Guide
```diff
# main.rs
-- use bevy_a11y::{
-- accesskit::{Node, Rect, Role},
-- AccessibilityNode,
-- };
++ use bevy_a11y::AccessibilityNode;
++ use accesskit::{Node, Rect, Role};
# Cargo.toml
++ accesskit = "0.17"
```
- Users will need to add `accesskit = "0.17"` to the dependencies
section of their `Cargo.toml` file and update their `accesskit` use
statements to come directly from the external crate instead of
`bevy_a11y`.
- Make sure to keep the versions of `accesskit` aligned with the
versions Bevy uses.
# Objective
- Checks screenshots on Windows
- Progress towards #15918
## Solution
- Checks screenshots on Windows
- Also disable the helmet gltf scene in windows ci as it doesn't work
# Objective
- Progress towards #15918
- Add tests for 3d
## Solution
- Add tests that cover lights, bloom, gltf and animation
- Removed examples `contributors` and `load_gltf` as they don't
contribute additional checks to CI
## Testing
- `CI_TESTING_CONFIG=.github/example-run/testbed_3d.ron cargo run
--example testbed_3d --features "bevy_ci_testing"`
# Objective
- Make progress for #15918
- Start with 2d
## Solution
- Remove screenshots for existing examples as they're not deterministic
- Create new "testbed" example category, with a 2d one to start
## Testing
- Run `CI_TESTING_CONFIG=.github/example-run/testbed_2d.ron cargo run
--example testbed_2d --features "bevy_ci_testing"`
- ???
- Check the screenshots