use bevy::{input::common_conditions::input_just_pressed, prelude::*};
use std::f32::consts::{FRAC_PI_2, PI, TAU};
const CONTAINER_SIZE: f32 = 150.0;
const HALF_CONTAINER_SIZE: f32 = CONTAINER_SIZE / 2.0;
const LOOP_LENGTH: f32 = 4.0;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.init_resource::<AnimationState>()
.add_systems(Startup, setup)
.add_systems(
Update,
(
toggle_overflow.run_if(input_just_pressed(KeyCode::KeyO)),
next_container_size.run_if(input_just_pressed(KeyCode::KeyS)),
update_transform::<Move>,
update_transform::<Scale>,
update_transform::<Rotate>,
update_animation,
),
)
.run();
}
#[derive(Component)]
struct Instructions;
#[derive(Resource, Default)]
struct AnimationState {
playing: bool,
paused_at: f32,
paused_total: f32,
t: f32,
}
#[derive(Component)]
struct Container(u8);
trait UpdateTransform {
fn update(&self, t: f32, transform: &mut Transform);
}
#[derive(Component)]
struct Move;
impl UpdateTransform for Move {
fn update(&self, t: f32, transform: &mut Transform) {
transform.translation.x = (t * TAU - FRAC_PI_2).sin() * HALF_CONTAINER_SIZE;
transform.translation.y = -(t * TAU - FRAC_PI_2).cos() * HALF_CONTAINER_SIZE;
}
}
#[derive(Component)]
struct Scale;
impl UpdateTransform for Scale {
fn update(&self, t: f32, transform: &mut Transform) {
transform.scale.x = 1.0 + 0.5 * (t * TAU).cos().max(0.0);
transform.scale.y = 1.0 + 0.5 * (t * TAU + PI).cos().max(0.0);
}
}
#[derive(Component)]
struct Rotate;
impl UpdateTransform for Rotate {
fn update(&self, t: f32, transform: &mut Transform) {
transform.rotation = Quat::from_axis_angle(Vec3::Z, ((t * TAU).cos() * 45.0).to_radians());
}
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
let text_style = TextStyle {
font_size: 20.,
..default()
};
commands.spawn((
TextBundle::from_sections([
TextSection::new(
"Next Overflow Setting (O)\nNext Container Size (S)\nToggle Animation (space)\n\n",
text_style.clone(),
),
TextSection::new(format!("{:?}", Overflow::clip()), text_style.clone()),
])
.with_style(Style {
position_type: PositionType::Absolute,
top: Val::Px(12.0),
left: Val::Px(12.0),
..default()
}),
Instructions,
));
commands
.spawn(NodeBundle {
style: Style {
width: Val::Percent(100.),
height: Val::Percent(100.),
justify_content: JustifyContent::Center,
align_items: AlignItems::Center,
..default()
},
..default()
})
.with_children(|parent| {
parent
.spawn(NodeBundle {
style: Style {
display: Display::Grid,
grid_template_columns: RepeatedGridTrack::px(3, CONTAINER_SIZE),
grid_template_rows: RepeatedGridTrack::px(2, CONTAINER_SIZE),
row_gap: Val::Px(80.),
column_gap: Val::Px(80.),
..default()
},
..default()
})
.with_children(|parent| {
spawn_image(parent, &asset_server, Move);
spawn_image(parent, &asset_server, Scale);
spawn_image(parent, &asset_server, Rotate);
spawn_text(parent, &asset_server, Move);
spawn_text(parent, &asset_server, Scale);
spawn_text(parent, &asset_server, Rotate);
});
});
}
fn spawn_image(
parent: &mut ChildBuilder,
asset_server: &Res<AssetServer>,
update_transform: impl UpdateTransform + Component,
) {
spawn_container(parent, update_transform, |parent| {
parent.spawn(ImageBundle {
image: UiImage::new(asset_server.load("branding/bevy_logo_dark_big.png")),
style: Style {
height: Val::Px(100.),
position_type: PositionType::Absolute,
top: Val::Px(-50.),
left: Val::Px(-200.),
..default()
},
..default()
});
});
}
fn spawn_text(
parent: &mut ChildBuilder,
asset_server: &Res<AssetServer>,
update_transform: impl UpdateTransform + Component,
) {
spawn_container(parent, update_transform, |parent| {
parent.spawn(TextBundle::from_section(
"Bevy",
TextStyle {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 120.0,
..default()
},
));
});
}
fn spawn_container(
parent: &mut ChildBuilder,
update_transform: impl UpdateTransform + Component,
spawn_children: impl FnOnce(&mut ChildBuilder),
) {
let mut transform = Transform::default();
update_transform.update(0.0, &mut transform);
parent
.spawn((
NodeBundle {
style: Style {
width: Val::Percent(100.),
height: Val::Percent(100.),
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
overflow: Overflow::clip(),
..default()
},
background_color: Color::srgb(0.25, 0.25, 0.25).into(),
..default()
},
Container(0),
))
.with_children(|parent| {
parent
.spawn((
NodeBundle {
style: Style {
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
top: Val::Px(transform.translation.x),
left: Val::Px(transform.translation.y),
..default()
},
transform,
..default()
},
update_transform,
))
.with_children(spawn_children);
});
}
fn update_animation(
mut animation: ResMut<AnimationState>,
time: Res<Time>,
keys: Res<ButtonInput<KeyCode>>,
) {
let delta = time.elapsed_seconds();
if keys.just_pressed(KeyCode::Space) {
animation.playing = !animation.playing;
if !animation.playing {
animation.paused_at = delta;
} else {
animation.paused_total += delta - animation.paused_at;
}
}
if animation.playing {
animation.t = (delta - animation.paused_total) % LOOP_LENGTH / LOOP_LENGTH;
}
}
fn update_transform<T: UpdateTransform + Component>(
animation: Res<AnimationState>,
mut containers: Query<(&mut Transform, &mut Style, &T)>,
) {
for (mut transform, mut style, update_transform) in &mut containers {
update_transform.update(animation.t, &mut transform);
style.left = Val::Px(transform.translation.x);
style.top = Val::Px(transform.translation.y);
}
}
fn toggle_overflow(
mut containers: Query<&mut Style, With<Container>>,
mut instructions: Query<&mut Text, With<Instructions>>,
) {
for mut style in &mut containers {
style.overflow = match style.overflow {
Overflow {
x: OverflowAxis::Visible,
y: OverflowAxis::Visible,
} => Overflow::clip_y(),
Overflow {
x: OverflowAxis::Visible,
y: OverflowAxis::Clip,
} => Overflow::clip_x(),
Overflow {
x: OverflowAxis::Clip,
y: OverflowAxis::Visible,
} => Overflow::clip(),
_ => Overflow::visible(),
};
let mut text = instructions.single_mut();
text.sections[1].value = format!("{:?}", style.overflow);
}
}
fn next_container_size(mut containers: Query<(&mut Style, &mut Container)>) {
for (mut style, mut container) in &mut containers {
container.0 = (container.0 + 1) % 3;
style.width = match container.0 {
2 => Val::Percent(30.),
_ => Val::Percent(100.),
};
style.height = match container.0 {
1 => Val::Percent(30.),
_ => Val::Percent(100.),
};
}
}