mirror of
https://github.com/bevyengine/bevy.git
synced 2026-06-30 07:45:50 -04:00
Carter Anderson
6c0eb84e31
# Objective `bsn!` currently generates a lot of new types: one for each patch, which then get assembled into a single Scene impl by composing them in a tuple. This gives the compiler more work to do (types to verify, code to generate, etc). It also makes our debug symbols bigger / harder to read. ## Solution Combine `bsn!` entries, where possible, into a single `SceneFunction<F>` implementation of `Scene`, which does all of the "scene patch" logic internally. This significantly cuts down on codegen, and also makes the functional behavior of a `bsn!` block more clear when expanded.
62 lines
1.6 KiB
Rust
62 lines
1.6 KiB
Rust
//! This example demonstrates how to use BSN to compose scenes.
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use bevy::{prelude::*, text::FontSourceTemplate};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_systems(Startup, scene.spawn())
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.run();
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}
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fn scene() -> impl SceneList {
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bsn_list![Camera2d, ui()]
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}
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fn ui() -> impl Scene {
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bsn! {
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Node {
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width: percent(100),
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height: percent(100),
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align_items: AlignItems::Center,
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justify_content: JustifyContent::Center,
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column_gap: px(5),
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}
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Children [
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(
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button("Ok")
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on(|_event: On<Pointer<Press>>| println!("Ok pressed!"))
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),
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(
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button("Cancel")
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on(|_event: On<Pointer<Press>>| println!("Cancel pressed!"))
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BackgroundColor(Color::srgb(0.4, 0.15, 0.15))
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),
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]
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}
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}
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fn button(label: &str) -> impl Scene {
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bsn! {
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Button
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Node {
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width: px(150),
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height: px(65),
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border: px(5),
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border_radius: BorderRadius::MAX,
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justify_content: JustifyContent::Center,
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align_items: AlignItems::Center,
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}
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BorderColor::from(Color::BLACK)
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BackgroundColor(Color::srgb(0.15, 0.15, 0.15))
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Children [(
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Text(label)
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TextFont {
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font: FontSourceTemplate::Handle("fonts/FiraSans-Bold.ttf"),
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font_size: px(33.0),
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}
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TextColor(Color::srgb(0.9, 0.9, 0.9))
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TextShadow
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)]
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}
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}
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