bevy/examples/3d/atmospheric_fog.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

110 lines
3.5 KiB
Rust

//! This example showcases atmospheric fog
//!
//! ## Controls
//!
//! | Key Binding | Action |
//! |:-------------------|:---------------------------------------|
//! | `Spacebar` | Toggle Atmospheric Fog |
//! | `S` | Toggle Directional Light Fog Influence |
use bevy::{
pbr::{CascadeShadowConfigBuilder, NotShadowCaster},
prelude::*,
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(
Startup,
(setup_camera_fog, setup_terrain_scene, setup_instructions),
)
.add_systems(Update, toggle_system)
.run();
}
fn setup_camera_fog(mut commands: Commands) {
commands.spawn((
Camera3d::default(),
Transform::from_xyz(-1.0, 0.1, 1.0).looking_at(Vec3::new(0.0, 0.0, 0.0), Vec3::Y),
DistanceFog {
color: Color::srgba(0.35, 0.48, 0.66, 1.0),
directional_light_color: Color::srgba(1.0, 0.95, 0.85, 0.5),
directional_light_exponent: 30.0,
falloff: FogFalloff::from_visibility_colors(
15.0, // distance in world units up to which objects retain visibility (>= 5% contrast)
Color::srgb(0.35, 0.5, 0.66), // atmospheric extinction color (after light is lost due to absorption by atmospheric particles)
Color::srgb(0.8, 0.844, 1.0), // atmospheric inscattering color (light gained due to scattering from the sun)
),
},
));
}
fn setup_terrain_scene(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
asset_server: Res<AssetServer>,
) {
// Configure a properly scaled cascade shadow map for this scene (defaults are too large, mesh units are in km)
let cascade_shadow_config = CascadeShadowConfigBuilder {
first_cascade_far_bound: 0.3,
maximum_distance: 3.0,
..default()
}
.build();
// Sun
commands.spawn((
DirectionalLight {
color: Color::srgb(0.98, 0.95, 0.82),
shadows_enabled: true,
..default()
},
Transform::from_xyz(0.0, 0.0, 0.0).looking_at(Vec3::new(-0.15, -0.05, 0.25), Vec3::Y),
cascade_shadow_config,
));
// Terrain
commands.spawn(SceneRoot(asset_server.load(
GltfAssetLabel::Scene(0).from_asset("models/terrain/Mountains.gltf"),
)));
// Sky
commands.spawn((
Mesh3d(meshes.add(Cuboid::new(2.0, 1.0, 1.0))),
MeshMaterial3d(materials.add(StandardMaterial {
base_color: Srgba::hex("888888").unwrap().into(),
unlit: true,
cull_mode: None,
..default()
})),
Transform::from_scale(Vec3::splat(20.0)),
NotShadowCaster,
));
}
fn setup_instructions(mut commands: Commands) {
commands.spawn((Text::new("Press Spacebar to Toggle Atmospheric Fog.\nPress S to Toggle Directional Light Fog Influence."),
Style {
position_type: PositionType::Absolute,
bottom: Val::Px(12.0),
left: Val::Px(12.0),
..default()
})
);
}
fn toggle_system(keycode: Res<ButtonInput<KeyCode>>, mut fog: Query<&mut DistanceFog>) {
let mut fog = fog.single_mut();
if keycode.just_pressed(KeyCode::Space) {
let a = fog.color.alpha();
fog.color.set_alpha(1.0 - a);
}
if keycode.just_pressed(KeyCode::KeyS) {
let a = fog.directional_light_color.alpha();
fog.directional_light_color.set_alpha(0.5 - a);
}
}