# Objective Implements border radius for UI nodes. Adopted from #8973, but excludes shadows. ## Solution - Add a component `BorderRadius` which contains a radius value for each corner of the UI node. - Use a fragment shader to generate the rounded corners using a signed distance function. <img width="50%" src="https://github.com/bevyengine/bevy/assets/26204416/16b2ba95-e274-4ce7-adb2-34cc41a776a5"></img> ## Changelog - `BorderRadius`: New component that holds the border radius values. - `NodeBundle` & `ButtonBundle`: Added a `border_radius: BorderRadius` field. - `extract_uinode_borders`: Stripped down, most of the work is done in the shader now. Borders are no longer assembled from multiple rects, instead the shader uses a signed distance function to draw the border. - `UiVertex`: Added size, border and radius fields. - `UiPipeline`: Added three vertex attributes to the vertex buffer layout, to accept the UI node's size, border thickness and border radius. - Examples: Added rounded corners to the UI element in the `button` example, and a `rounded_borders` example. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Zachary Harrold <zac@harrold.com.au> Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
		
			
				
	
	
		
			93 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! This example illustrates how to create a button that changes color and text based on its
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//! interaction state.
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use bevy::{color::palettes::basic::*, prelude::*, winit::WinitSettings};
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fn main() {
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    App::new()
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        .add_plugins(DefaultPlugins)
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        // Only run the app when there is user input. This will significantly reduce CPU/GPU use.
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        .insert_resource(WinitSettings::desktop_app())
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        .add_systems(Startup, setup)
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        .add_systems(Update, button_system)
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        .run();
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}
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const NORMAL_BUTTON: Color = Color::srgb(0.15, 0.15, 0.15);
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const HOVERED_BUTTON: Color = Color::srgb(0.25, 0.25, 0.25);
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const PRESSED_BUTTON: Color = Color::srgb(0.35, 0.75, 0.35);
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fn button_system(
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    mut interaction_query: Query<
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        (&Interaction, &mut UiImage, &mut BorderColor, &Children),
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        (Changed<Interaction>, With<Button>),
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    >,
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    mut text_query: Query<&mut Text>,
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) {
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    for (interaction, mut image, mut border_color, children) in &mut interaction_query {
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        let mut text = text_query.get_mut(children[0]).unwrap();
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        match *interaction {
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            Interaction::Pressed => {
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                text.sections[0].value = "Press".to_string();
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                image.color = PRESSED_BUTTON;
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                border_color.0 = RED.into();
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            }
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            Interaction::Hovered => {
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                text.sections[0].value = "Hover".to_string();
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                image.color = HOVERED_BUTTON;
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                border_color.0 = Color::WHITE;
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            }
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            Interaction::None => {
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                text.sections[0].value = "Button".to_string();
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                image.color = NORMAL_BUTTON;
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                border_color.0 = Color::BLACK;
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            }
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        }
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    }
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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    // ui camera
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    commands.spawn(Camera2dBundle::default());
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    commands
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        .spawn(NodeBundle {
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            style: Style {
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                width: Val::Percent(100.0),
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                height: Val::Percent(100.0),
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                align_items: AlignItems::Center,
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                justify_content: JustifyContent::Center,
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                ..default()
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            },
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            ..default()
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        })
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        .with_children(|parent| {
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            parent
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                .spawn(ButtonBundle {
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                    style: Style {
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                        width: Val::Px(150.0),
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                        height: Val::Px(65.0),
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                        border: UiRect::all(Val::Px(5.0)),
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                        // horizontally center child text
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                        justify_content: JustifyContent::Center,
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                        // vertically center child text
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                        align_items: AlignItems::Center,
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                        ..default()
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                    },
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                    border_color: BorderColor(Color::BLACK),
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                    border_radius: BorderRadius::MAX,
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                    image: UiImage::default().with_color(NORMAL_BUTTON),
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                    ..default()
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                })
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                .with_children(|parent| {
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                    parent.spawn(TextBundle::from_section(
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                        "Button",
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                        TextStyle {
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                            font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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                            font_size: 40.0,
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                            color: Color::srgb(0.9, 0.9, 0.9),
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                        },
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                    ));
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                });
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        });
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}
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