bevy/examples/2d/2d_shapes.rs
UkoeHB c2c19e5ae4
Text rework (#15591)
**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>
2024-10-09 18:35:36 +00:00

86 lines
2.5 KiB
Rust

//! Shows how to render simple primitive shapes with a single color.
//!
//! You can toggle wireframes with the space bar except on wasm. Wasm does not support
//! `POLYGON_MODE_LINE` on the gpu.
use bevy::prelude::*;
#[cfg(not(target_arch = "wasm32"))]
use bevy::sprite::{Wireframe2dConfig, Wireframe2dPlugin};
fn main() {
let mut app = App::new();
app.add_plugins((
DefaultPlugins,
#[cfg(not(target_arch = "wasm32"))]
Wireframe2dPlugin,
))
.add_systems(Startup, setup);
#[cfg(not(target_arch = "wasm32"))]
app.add_systems(Update, toggle_wireframe);
app.run();
}
const X_EXTENT: f32 = 900.;
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<ColorMaterial>>,
) {
commands.spawn(Camera2d);
let shapes = [
meshes.add(Circle::new(50.0)),
meshes.add(CircularSector::new(50.0, 1.0)),
meshes.add(CircularSegment::new(50.0, 1.25)),
meshes.add(Ellipse::new(25.0, 50.0)),
meshes.add(Annulus::new(25.0, 50.0)),
meshes.add(Capsule2d::new(25.0, 50.0)),
meshes.add(Rhombus::new(75.0, 100.0)),
meshes.add(Rectangle::new(50.0, 100.0)),
meshes.add(RegularPolygon::new(50.0, 6)),
meshes.add(Triangle2d::new(
Vec2::Y * 50.0,
Vec2::new(-50.0, -50.0),
Vec2::new(50.0, -50.0),
)),
];
let num_shapes = shapes.len();
for (i, shape) in shapes.into_iter().enumerate() {
// Distribute colors evenly across the rainbow.
let color = Color::hsl(360. * i as f32 / num_shapes as f32, 0.95, 0.7);
commands.spawn((
Mesh2d(shape),
MeshMaterial2d(materials.add(color)),
Transform::from_xyz(
// Distribute shapes from -X_EXTENT/2 to +X_EXTENT/2.
-X_EXTENT / 2. + i as f32 / (num_shapes - 1) as f32 * X_EXTENT,
0.0,
0.0,
),
));
}
#[cfg(not(target_arch = "wasm32"))]
commands.spawn((
Text::new("Press space to toggle wireframes"),
Style {
position_type: PositionType::Absolute,
top: Val::Px(12.0),
left: Val::Px(12.0),
..default()
},
));
}
#[cfg(not(target_arch = "wasm32"))]
fn toggle_wireframe(
mut wireframe_config: ResMut<Wireframe2dConfig>,
keyboard: Res<ButtonInput<KeyCode>>,
) {
if keyboard.just_pressed(KeyCode::Space) {
wireframe_config.global = !wireframe_config.global;
}
}