# Objective
Add responsive font sizes supporting rem and viewport units to
`bevy_text` with minimal changes to the APIs and systems.
## Solution
Introduce a new `FontSize` enum:
```rust
pub enum FontSize {
/// Font Size in logical pixels.
Px(f32),
/// Font size as a percentage of the viewport width.
Vw(f32),
/// Font size as a percentage of the viewport height.
Vh(f32),
/// Font size as a percentage of the smaller of the viewport width and height.
VMin(f32),
/// Font size as a percentage of the larger of the viewport width and height.
VMax(f32),
/// Font Size relative to the value of the `RemSize` resource.
Rem(f32),
}
```
This replaces the `f32` value of `TextFont`'s `font_size` field.
The viewport variants work the same way as their respective `Val`
counterparts.
`Rem` values are multiplied by the value of the `RemSize` resource
(which newtypes an `f32`).
`FontSize` provides an `eval` method that takes a logical viewport size
and rem base size and returns an `f32` logical font size. The resolved
logical font size is then written into the `Attributes` passed to Cosmic
Text by `TextPipeline::update_buffer`.
Any text implementation using `bevy_text` must now provide viewport and
rem base values when calling `TextPipeline::update_buffer` or
`create_measure`.
`Text2d` uses the size of the primary window to resolve viewport values
(or `Vec2::splat(1000)` if no primary window is found). This is a
deliberate compromise, a single `Text2d` can be rendered to multiple
viewports using `RenderLayers`, so it's difficult to find a rule for
which viewport size should be chosen.
### Change detection
`ComputedTextBlock` has two new fields: `uses_viewport_sizes` and
`uses_rem_sizes`, which are set to true in `TextPipeline::update_buffer`
iff any text section in the block uses viewport or rem font sizes,
respectively.
The `ComputedTextBlock::needs_rerender` method has been modified to take
take two bool parameters:
```rust
pub fn needs_rerender(
&self,
is_viewport_size_changed: bool,
is_rem_size_changed: bool,
) -> bool {
self.needs_rerender
|| (is_viewport_size_changed && self.uses_viewport_sizes)
|| (is_rem_size_changed && self.uses_rem_sizes)
}
```
This ensures that text reupdates will also be scheduled if one of the text section's uses a viewport font size and the local viewport size changed, or if one of the text section's uses a rem font size and the rem size changed.
#### Limitations
There are some limitations because we don't have any sort of font style inheritance yet:
* "rem" units aren't proper rem units, and just based on the value of a resource.
* "em" units are resolved based on inherited font size, so can't be implemented without inheritance support.
#### Notes
* This PR is quite small and not very technical. Reviewers don't need to be especially familiar with `bevy_text`. Most of the changes are to the examples.
* We could consider using `Val` instead of `FontSize`, then we could use `Val`'s constructor functions which would be much nicer, but some variants might not have sensible interpretations in both UI and Text2d contexts. Also we'd have to make `Val` accessible to `bevy_text`.
## Testing
The changes to the text systems are relatively trivial and easy to understand. I already added a minor change to the `text` example to use `Vh` font size for the "hello bevy" text in the bottom right corner. If you change the size of the window, you should see the text change size in response. The text initially flickers before it updates because of some unrelated asset/image changes that mean that font textures aren't ready until the frame after the text update that changes the font size.
Most of the example migrations were automated using regular expressions, and there are bound to be mistakes in those changes. It's infeasible to check every single example thoroughly, but it's early enough in the release cycle that I don't think we should be too worried if a few bugs slip in.
---------
Co-authored-by: Kevin Chen <chen.kevin.f@gmail.com>
# Objective
works on #18238
## Solution
convert calls to `.with_children` to use the `Children::spawn` or
`Children::spawn_one` types or `children!` macro.
This touches the `window`, `2d`, `animation` folders, as well as
`ecs/one_shot_systems.rs`.
`observer_propagation.rs` looks like exactly what `with_children` is
useful for, so I deliberately haven't touched it.
I can break this up into more PRs or squash if desired.
## Testing
I've run the examples before and after this patch and verified visually
that nothing has changed
# Objective
- Allow the `Val`-helper functions to accept more types besides just
`f32`
Fixes#20549
## Solution
- Adds a new trait that can be implemented for numbers
- That trait has a method that converts `self` to `f32`
## Testing
- I tested it using Rust's testing framework (although I didn't leave
the tests in, as I don't deem them important enough)
<details>
<summary>Rust test</summary>
```rust
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_val_helpers_work() {
let p = px(10_u8);
assert_eq!(p, Val::Px(10.0));
let p = px(10_u16);
assert_eq!(p, Val::Px(10.0));
let p = px(10_u32);
assert_eq!(p, Val::Px(10.0));
let p = px(10_u64);
assert_eq!(p, Val::Px(10.0));
let p = px(10_u128);
assert_eq!(p, Val::Px(10.0));
let p = px(10_i8);
assert_eq!(p, Val::Px(10.0));
let p = px(10_i16);
assert_eq!(p, Val::Px(10.0));
let p = px(10_i32);
assert_eq!(p, Val::Px(10.0));
let p = px(10_i64);
assert_eq!(p, Val::Px(10.0));
let p = px(10_i128);
assert_eq!(p, Val::Px(10.0));
let p = px(10.3_f32);
assert_eq!(p, Val::Px(10.3));
let p = px(10.6_f64);
assert_eq!(p, Val::Px(10.6));
}
}
```
</details>
---
## Showcase
```rust
// Same as Val::Px(10.)
px(10);
px(10_u8);
px(10.0);
```
# Objective
- In #17743, attention was raised to the fact that we supported an
unusual kind of step easing function. The author of the fix kindly
provided some links to standards used in CSS. It would be desirable to
support generally agreed upon standards so this PR here tries to
implement an extra configuration option of the step easing function
- Resolve#17744
## Solution
- Introduce `StepConfig`
- `StepConfig` can configure both the number of steps and the jumping
behavior of the function
- `StepConfig` replaces the raw `usize` parameter of the
`EasingFunction::Steps(usize)` construct.
- `StepConfig`s default jumping behavior is `end`, so in that way it
follows #17743
## Testing
- I added a new test per `JumpAt` jumping behavior. These tests
replicate the visuals that can be found at
https://developer.mozilla.org/en-US/docs/Web/CSS/easing-function/steps#description
## Migration Guide
- `EasingFunction::Steps` now uses a `StepConfig` instead of a raw
`usize`. You can replicate the previous behavior by replaceing
`EasingFunction::Steps(10)` with
`EasingFunction::Steps(StepConfig::new(10))`.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
After #17461, the ease function labels in this example are a bit
cramped, especially in the bottom row.
This adjusts the spacing slightly and centers the labels.
## Solution
- The label is now a child of the plot and they are drawn around the
center of the transform
- Plot size and extents are now constants, and this thing has been
banished:
```rust
i as f32 * 95.0 - 1280.0 / 2.0 + 25.0,
-100.0 - ((j as f32 * 250.0) - 300.0),
0.0,
```
- There's room for expansion in another row, so make that easier by
doing the chunking by row
- Other misc tidying of variable names, sprinkled in a few comments,
etc.
## Before
<img width="1280" alt="Screenshot 2025-02-08 at 7 33 14 AM"
src="https://github.com/user-attachments/assets/0b79c619-d295-4ab1-8cd1-d23c862d06c5"
/>
## After
<img width="1280" alt="Screenshot 2025-02-08 at 7 32 45 AM"
src="https://github.com/user-attachments/assets/656ef695-9aa8-42e9-b867-1718294316bd"
/>
# Objective
The docs of `EaseFunction` don't visualize the different functions,
requiring you to check out the Bevy repo and running the
`easing_function` example.
## Solution
- Add tool to generate suitable svg graphs. This only needs to be re-run
when adding new ease functions.
- works with all themes
- also add missing easing functions to example.
---
## Showcase
---------
Co-authored-by: François Mockers <mockersf@gmail.com>
# Objective
We currently use special "floating" constructors for `EasingCurve`,
`FunctionCurve`, and `ConstantCurve` (ex: `easing_curve`). This erases
the type being created (and in general "what is happening"
structurally), for very minimal ergonomics improvements. With rare
exceptions, we prefer normal `X::new()` constructors over floating `x()`
constructors in Bevy. I don't think this use case merits special casing
here.
## Solution
Add `EasingCurve::new()`, use normal constructors everywhere, and remove
the floating constructors.
I think this should land in 0.15 in the interest of not breaking people
later.
# 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();
}
}
```
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)
# Objective
Currently text is recomputed unnecessarily on any changes to its color,
which is extremely expensive.
## Solution
Split up `TextStyle` into two separate components `TextFont` and
`TextColor`.
## Testing
I added this system to `many_buttons`:
```rust
fn set_text_colors_changed(mut colors: Query<&mut TextColor>) {
for mut text_color in colors.iter_mut() {
text_color.set_changed();
}
}
```
reports ~4fps on main, ~50fps with this PR.
## Migration Guide
`TextStyle` has been renamed to `TextFont` and its `color` field has
been moved to a separate component named `TextColor` which newtypes
`Color`.
**Ready for review. Examples migration progress: 100%.**
# Objective
- Implement https://github.com/bevyengine/bevy/discussions/15014
## Solution
This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.
Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.
## Testing
- [x] Text examples all work.
---
## Showcase
TODO: showcase-worthy
## Migration Guide
TODO: very breaking
### Accessing text spans by index
Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.
Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
let text = query.single_mut();
text.sections[1].value = format_time(time.elapsed());
}
```
After:
```rust
fn refresh_text(
query: Query<Entity, With<TimeText>>,
mut writer: UiTextWriter,
time: Res<Time>
) {
let entity = query.single();
*writer.text(entity, 1) = format_time(time.elapsed());
}
```
### Iterating text spans
Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Continue migration of bevy APIs to required components, following
guidance of https://hackmd.io/@bevy/required_components/
## Solution
- Make `Sprite` require `Transform` and `Visibility` and
`SyncToRenderWorld`
- move image and texture atlas handles into `Sprite`
- deprecate `SpriteBundle`
- remove engine uses of `SpriteBundle`
## Testing
ran cargo tests on bevy_sprite and tested several sprite examples.
---
## Migration Guide
Replace all uses of `SpriteBundle` with `Sprite`. There are several new
convenience constructors: `Sprite::from_image`,
`Sprite::from_atlas_image`, `Sprite::from_color`.
WARNING: use of `Handle<Image>` and `TextureAtlas` as components on
sprite entities will NO LONGER WORK. Use the fields on `Sprite` instead.
I would have removed the `Component` impls from `TextureAtlas` and
`Handle<Image>` except it is still used within ui. We should fix this
moving forward with the migration.
# Objective
- After #15711 which added a column to the example, the point of a curve
was too close to the next curve
## Solution
- Make it closer to its own
# Objective
Simplify the API surrounding easing curves. Broaden the base of types
that support easing.
## Solution
There is now a single library function, `easing_curve`, which constructs
a unit-parametrized easing curve between two values based on an
`EaseFunction`:
```rust
/// Given a `start` and `end` value, create a curve parametrized over [the unit interval]
/// that connects them, using the given [ease function] to determine the form of the
/// curve in between.
///
/// [the unit interval]: Interval::UNIT
/// [ease function]: EaseFunction
pub fn easing_curve<T: Ease>(start: T, end: T, ease_fn: EaseFunction) -> EasingCurve<T> { //... }
```
As this shows, the type of the output curve is generic only in `T`. In
particular, as long as `T` is `Reflect` (and `FromReflect` etc. — i.e.,
a standard "well-behaved" reflectable type), `EasingCurve<T>` is also
`Reflect`, and there is no special field handling nonsense. Therefore,
`EasingCurve` is the kind of thing that would be able to be easily
changed in an editor. This is made possible by storing the actual
`EaseFunction` on `EasingCurve<T>` instead of indirecting through some
kind of function type (which generally leads to issues with reflection).
The types that can be eased are those that implement a trait `Ease`:
```rust
/// A type whose values can be eased between.
///
/// This requires the construction of an interpolation curve that actually extends
/// beyond the curve segment that connects two values, because an easing curve may
/// extrapolate before the starting value and after the ending value. This is
/// especially common in easing functions that mimic elastic or springlike behavior.
pub trait Ease: Sized {
/// Given `start` and `end` values, produce a curve with [unlimited domain]
/// that:
/// - takes a value equivalent to `start` at `t = 0`
/// - takes a value equivalent to `end` at `t = 1`
/// - has constant speed everywhere, including outside of `[0, 1]`
///
/// [unlimited domain]: Interval::EVERYWHERE
fn interpolating_curve_unbounded(start: &Self, end: &Self) -> impl Curve<Self>;
}
```
(I know, I know, yet *another* interpolation trait. See 'Future
direction'.)
The other existing easing functions from the previous version of this
module have also become new members of `EaseFunction`: `Linear`,
`Steps`, and `Elastic` (which maybe needs a different name). The latter
two are parametrized.
## Testing
Tested using the `easing_functions` example. I also axed the
`cubic_curve` example which was of questionable value and replaced it
with `eased_motion`, which uses this API in the context of animation:
https://github.com/user-attachments/assets/3c802992-6b9b-4b56-aeb1-a47501c29ce2
---
## Future direction
Morally speaking, `Ease` is incredibly similar to `StableInterpolate`.
Probably, we should just merge `StableInterpolate` into `Ease`, and then
make `SmoothNudge` an automatic extension trait of `Ease`. The reason I
didn't do that is that `StableInterpolate` is not implemented for
`VectorSpace` because of concerns about the `Color` types, and I wanted
to avoid controversy. I think that may be a good idea though.
As Alice mentioned before, we should also probably get rid of the
`interpolation` dependency.
The parametrized `Elastic` variant probably also needs some additional
work (e.g. renaming, in/out/in-out variants, etc.) if we want to keep
it.
ickshonpe
