992681b59b
*This PR description is an edited copy of #5007, written by @alice-i-cecile.* # Objective Follow-up to https://github.com/bevyengine/bevy/pull/2254. The `Resource` trait currently has a blanket implementation for all types that meet its bounds. While ergonomic, this results in several drawbacks: * it is possible to make confusing, silent mistakes such as inserting a function pointer (Foo) rather than a value (Foo::Bar) as a resource * it is challenging to discover if a type is intended to be used as a resource * we cannot later add customization options (see the [RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/27-derive-component.md) for the equivalent choice for Component). * dependencies can use the same Rust type as a resource in invisibly conflicting ways * raw Rust types used as resources cannot preserve privacy appropriately, as anyone able to access that type can read and write to internal values * we cannot capture a definitive list of possible resources to display to users in an editor ## Notes to reviewers * Review this commit-by-commit; there's effectively no back-tracking and there's a lot of churn in some of these commits. *ira: My commits are not as well organized :')* * I've relaxed the bound on Local to Send + Sync + 'static: I don't think these concerns apply there, so this can keep things simple. Storing e.g. a u32 in a Local is fine, because there's a variable name attached explaining what it does. * I think this is a bad place for the Resource trait to live, but I've left it in place to make reviewing easier. IMO that's best tackled with https://github.com/bevyengine/bevy/issues/4981. ## Changelog `Resource` is no longer automatically implemented for all matching types. Instead, use the new `#[derive(Resource)]` macro. ## Migration Guide Add `#[derive(Resource)]` to all types you are using as a resource. If you are using a third party type as a resource, wrap it in a tuple struct to bypass orphan rules. Consider deriving `Deref` and `DerefMut` to improve ergonomics. `ClearColor` no longer implements `Component`. Using `ClearColor` as a component in 0.8 did nothing. Use the `ClearColorConfig` in the `Camera3d` and `Camera2d` components instead. Co-authored-by: Alice <alice.i.cecile@gmail.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: devil-ira <justthecooldude@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
94 lines
2.8 KiB
Rust
94 lines
2.8 KiB
Rust
//! This example illustrates how `FontAtlas`'s are populated.
|
|
//! Bevy uses `FontAtlas`'s under the hood to optimize text rendering.
|
|
|
|
use bevy::{prelude::*, text::FontAtlasSet};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.init_resource::<State>()
|
|
.insert_resource(ClearColor(Color::BLACK))
|
|
.add_plugins(DefaultPlugins)
|
|
.add_startup_system(setup)
|
|
.add_system(text_update_system)
|
|
.add_system(atlas_render_system)
|
|
.run();
|
|
}
|
|
|
|
#[derive(Resource)]
|
|
struct State {
|
|
atlas_count: u32,
|
|
handle: Handle<Font>,
|
|
timer: Timer,
|
|
}
|
|
|
|
impl Default for State {
|
|
fn default() -> Self {
|
|
Self {
|
|
atlas_count: 0,
|
|
handle: Handle::default(),
|
|
timer: Timer::from_seconds(0.05, true),
|
|
}
|
|
}
|
|
}
|
|
|
|
fn atlas_render_system(
|
|
mut commands: Commands,
|
|
mut state: ResMut<State>,
|
|
font_atlas_sets: Res<Assets<FontAtlasSet>>,
|
|
texture_atlases: Res<Assets<TextureAtlas>>,
|
|
) {
|
|
if let Some(set) = font_atlas_sets.get(&state.handle.as_weak::<FontAtlasSet>()) {
|
|
if let Some((_size, font_atlas)) = set.iter().next() {
|
|
let x_offset = state.atlas_count as f32;
|
|
if state.atlas_count == font_atlas.len() as u32 {
|
|
return;
|
|
}
|
|
let texture_atlas = texture_atlases
|
|
.get(&font_atlas[state.atlas_count as usize].texture_atlas)
|
|
.unwrap();
|
|
state.atlas_count += 1;
|
|
commands.spawn_bundle(ImageBundle {
|
|
image: texture_atlas.texture.clone().into(),
|
|
style: Style {
|
|
position_type: PositionType::Absolute,
|
|
position: UiRect {
|
|
top: Val::Px(0.0),
|
|
left: Val::Px(512.0 * x_offset),
|
|
..default()
|
|
},
|
|
..default()
|
|
},
|
|
..default()
|
|
});
|
|
}
|
|
}
|
|
}
|
|
|
|
fn text_update_system(mut state: ResMut<State>, time: Res<Time>, mut query: Query<&mut Text>) {
|
|
if state.timer.tick(time.delta()).finished() {
|
|
for mut text in &mut query {
|
|
let c = rand::random::<u8>() as char;
|
|
let string = &mut text.sections[0].value;
|
|
if !string.contains(c) {
|
|
string.push(c);
|
|
}
|
|
}
|
|
|
|
state.timer.reset();
|
|
}
|
|
}
|
|
|
|
fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut state: ResMut<State>) {
|
|
let font_handle = asset_server.load("fonts/FiraSans-Bold.ttf");
|
|
state.handle = font_handle.clone();
|
|
commands.spawn_bundle(Camera2dBundle::default());
|
|
commands.spawn_bundle(TextBundle::from_section(
|
|
"a",
|
|
TextStyle {
|
|
font: font_handle,
|
|
font_size: 60.0,
|
|
color: Color::YELLOW,
|
|
},
|
|
));
|
|
}
|