target ui indicating health too (#17)

src/aim/target_ui.rs

@@ -0,0 +1,160 @@
+use super::AimState;
+use crate::{
+    backpack::BackpackHead,
+    heads_ui::HeadsImages,
+    npc::{Hitpoints, NpcHead},
+};
+use bevy::prelude::*;
+
+#[derive(Component, Reflect, Default)]
+#[reflect(Component)]
+struct HeadImage;
+
+#[derive(Component, Reflect, Default)]
+#[reflect(Component)]
+struct HeadDamage;
+
+#[derive(Resource, Default, PartialEq)]
+struct TargetUi {
+    head: Option<BackpackHead>,
+}
+
+pub fn plugin(app: &mut App) {
+    app.add_systems(Startup, setup);
+    app.add_systems(Update, (sync, update));
+}
+
+fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    let bg = asset_server.load("ui/head_bg.png");
+    let regular = asset_server.load("ui/head_regular.png");
+    let damage = asset_server.load("ui/head_damage.png");
+
+    commands
+        .spawn((
+            Name::new("target-ui"),
+            Node {
+                position_type: PositionType::Absolute,
+                top: Val::Px(150.0),
+                left: Val::Px(20.0),
+                height: Val::Px(74.0),
+                ..default()
+            },
+        ))
+        .with_children(|parent| {
+            spawn_head_ui(parent, bg.clone(), regular.clone(), damage.clone());
+        });
+
+    commands.insert_resource(TargetUi::default());
+}
+
+fn spawn_head_ui(
+    parent: &mut ChildBuilder,
+    bg: Handle<Image>,
+    regular: Handle<Image>,
+    damage: Handle<Image>,
+) {
+    const SIZE: f32 = 90.0;
+    const DAMAGE_SIZE: f32 = 74.0;
+
+    parent
+        .spawn((Node {
+            position_type: PositionType::Relative,
+            justify_content: JustifyContent::Center,
+            align_items: AlignItems::Center,
+            width: Val::Px(SIZE),
+            ..default()
+        },))
+        .with_children(|parent| {
+            parent.spawn((
+                Node {
+                    position_type: PositionType::Absolute,
+                    ..default()
+                },
+                ImageNode::new(bg),
+            ));
+            parent.spawn((
+                Node {
+                    position_type: PositionType::Absolute,
+                    ..default()
+                },
+                ImageNode::default(),
+                Visibility::Hidden,
+                HeadImage,
+            ));
+            parent.spawn((
+                Node {
+                    position_type: PositionType::Absolute,
+                    ..default()
+                },
+                ImageNode::new(regular),
+            ));
+            parent
+                .spawn((Node {
+                    height: Val::Px(DAMAGE_SIZE),
+                    width: Val::Px(DAMAGE_SIZE),
+                    ..default()
+                },))
+                .with_children(|parent| {
+                    parent
+                        .spawn((
+                            HeadDamage,
+                            Node {
+                                position_type: PositionType::Absolute,
+                                display: Display::Block,
+                                overflow: Overflow::clip(),
+                                top: Val::Px(0.),
+                                left: Val::Px(0.),
+                                right: Val::Px(0.),
+                                height: Val::Percent(25.),
+                                ..default()
+                            },
+                        ))
+                        .with_child(ImageNode::new(damage));
+                });
+        });
+}
+
+fn update(
+    target: Res<TargetUi>,
+    heads_images: Res<HeadsImages>,
+    mut head_image: Query<
+        (&mut Visibility, &mut ImageNode),
+        (Without<HeadDamage>, With<HeadImage>),
+    >,
+    mut head_damage: Query<&mut Node, (With<HeadDamage>, Without<HeadImage>)>,
+) {
+    if target.is_changed() {
+        if let Ok((mut vis, mut image)) = head_image.get_single_mut() {
+            if let Some(head) = target.head {
+                *vis = Visibility::Visible;
+                image.image = heads_images.heads[head.head].clone();
+            } else {
+                *vis = Visibility::Hidden;
+            }
+        }
+
+        if let Ok(mut node) = head_damage.get_single_mut() {
+            node.height = Val::Percent(target.head.map(|head| head.damage()).unwrap_or(0.) * 100.);
+        }
+    }
+}
+
+fn sync(
+    mut target: ResMut<TargetUi>,
+    aim: Res<AimState>,
+    target_data: Query<(&Hitpoints, &NpcHead)>,
+) {
+    let mut new_state = None;
+    if let Some(e) = aim.target {
+        if let Ok((hp, head)) = target_data.get(e) {
+            new_state = Some(BackpackHead {
+                head: head.0,
+                health: hp.health(),
+            });
+        }
+    }
+
+    if new_state != target.head {
+        target.head = new_state;
+    }
+}