cyber_rider/src/ui.rs

use bevy::prelude::*;

use crate::{action::CyberBikeState, geometry::PLANET_RADIUS};

#[derive(Component)]
struct UpText;

fn setup_ui(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn_bundle(UiCameraBundle::default());

    commands
        .spawn_bundle(TextBundle {
            style: Style {
                align_self: AlignSelf::FlexEnd,
                ..Default::default()
            },
            // Use `Text` directly
            text: Text {
                // Construct a `Vec` of `TextSection`s
                sections: vec![TextSection {
                    value: "".to_string(),
                    style: TextStyle {
                        font: asset_server.load("fonts/FiraMono-Medium.ttf"),
                        font_size: 40.0,
                        color: Color::GOLD,
                    },
                }],
                ..Default::default()
            },
            ..Default::default()
        })
        .insert(UpText);
}

fn update_ui(
    state_query: Query<(&CyberBikeState, &Transform)>,
    mut text_query: Query<&mut Text, With<UpText>>,
) {
    let mut text = text_query.single_mut();
    let state = state_query.single();
    text.sections[0].value = format!(
        "spd: {:.2}\nalt: {:.2}",
        state.0.velocity.length(),
        state.1.translation.length() - PLANET_RADIUS
    );
}

pub struct CyberUIPlugin;

impl Plugin for CyberUIPlugin {
    fn build(&self, app: &mut App) {
        app.add_startup_system(setup_ui).add_system(update_ui);
    }
}