refactor: move animation components into new systems/animation submodule

src/systems/animation/blinking.rs

@@ -0,0 +1,82 @@
+use bevy_ecs::{
+    component::Component,
+    entity::Entity,
+    query::{Has, With},
+    system::{Commands, Query, Res},
+};
+
+use crate::systems::{DeltaTime, Frozen, Hidden, Renderable};
+
+#[derive(Component, Debug)]
+pub struct Blinking {
+    pub tick_timer: u32,
+    pub interval_ticks: u32,
+}
+
+impl Blinking {
+    pub fn new(interval_ticks: u32) -> Self {
+        Self {
+            tick_timer: 0,
+            interval_ticks,
+        }
+    }
+}
+
+/// Updates blinking entities by toggling their visibility at regular intervals.
+///
+/// This system manages entities that have both `Blinking` and `Renderable` components,
+/// accumulating ticks and toggling visibility when the specified interval is reached.
+/// Uses integer arithmetic for deterministic behavior.
+#[allow(clippy::type_complexity)]
+pub fn blinking_system(
+    mut commands: Commands,
+    time: Res<DeltaTime>,
+    mut query: Query<(Entity, &mut Blinking, Has<Hidden>, Has<Frozen>), With<Renderable>>,
+) {
+    for (entity, mut blinking, hidden, frozen) in query.iter_mut() {
+        // If the entity is frozen, blinking is disabled and the entity is unhidden (if it was hidden)
+        if frozen {
+            if hidden {
+                commands.entity(entity).remove::<Hidden>();
+            }
+
+            continue;
+        }
+
+        // Increase the timer by the delta ticks
+        blinking.tick_timer += time.ticks;
+
+        // Handle zero interval case (immediate toggling)
+        if blinking.interval_ticks == 0 {
+            if time.ticks > 0 {
+                if hidden {
+                    commands.entity(entity).remove::<Hidden>();
+                } else {
+                    commands.entity(entity).insert(Hidden);
+                }
+            }
+            continue;
+        }
+
+        // Calculate how many complete intervals have passed
+        let complete_intervals = blinking.tick_timer / blinking.interval_ticks;
+
+        // If no complete intervals have passed, there's nothing to do yet
+        if complete_intervals == 0 {
+            continue;
+        }
+
+        // Update the timer to the remainder after complete intervals
+        blinking.tick_timer %= blinking.interval_ticks;
+
+        // Toggle the Hidden component for each complete interval
+        // Since toggling twice is a no-op, we only need to toggle if the count is odd
+        if complete_intervals % 2 == 1 {
+            if hidden {
+                commands.entity(entity).remove::<Hidden>();
+            } else {
+                commands.entity(entity).insert(Hidden);
+            }
+        }
+    }
+}