feat: ghosts system

src/systems/components.rs

@@ -11,6 +11,65 @@ use crate::{
 #[derive(Default, Component)]
 pub struct PlayerControlled;
 
+/// The four classic ghost types.
+#[derive(Component, Debug, Clone, Copy, PartialEq, Eq)]
+pub enum GhostType {
+    Blinky,
+    Pinky,
+    Inky,
+    Clyde,
+}
+
+impl GhostType {
+    /// Returns the ghost type name for atlas lookups.
+    pub fn as_str(self) -> &'static str {
+        match self {
+            GhostType::Blinky => "blinky",
+            GhostType::Pinky => "pinky",
+            GhostType::Inky => "inky",
+            GhostType::Clyde => "clyde",
+        }
+    }
+
+    /// Returns the base movement speed for this ghost type.
+    pub fn base_speed(self) -> f32 {
+        match self {
+            GhostType::Blinky => 1.0,
+            GhostType::Pinky => 0.95,
+            GhostType::Inky => 0.9,
+            GhostType::Clyde => 0.85,
+        }
+    }
+
+    /// Returns the ghost's color for debug rendering.
+    pub fn debug_color(&self) -> sdl2::pixels::Color {
+        match self {
+            GhostType::Blinky => sdl2::pixels::Color::RGB(255, 0, 0),    // Red
+            GhostType::Pinky => sdl2::pixels::Color::RGB(255, 182, 255), // Pink
+            GhostType::Inky => sdl2::pixels::Color::RGB(0, 255, 255),    // Cyan
+            GhostType::Clyde => sdl2::pixels::Color::RGB(255, 182, 85),  // Orange
+        }
+    }
+}
+
+/// Ghost AI behavior component - controls randomized movement decisions.
+#[derive(Component)]
+pub struct GhostBehavior {
+    /// Timer for making new direction decisions
+    pub decision_timer: f32,
+    /// Interval between direction decisions (in seconds)
+    pub decision_interval: f32,
+}
+
+impl Default for GhostBehavior {
+    fn default() -> Self {
+        Self {
+            decision_timer: 0.0,
+            decision_interval: 0.5, // Make decisions every half second
+        }
+    }
+}
+
 /// A tag component denoting the type of entity.
 #[derive(Component, Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum EntityType {
@@ -94,6 +153,20 @@ pub struct ItemBundle {
     pub item_collider: ItemCollider,
 }
 
+#[derive(Bundle)]
+pub struct GhostBundle {
+    pub ghost_type: GhostType,
+    pub ghost_behavior: GhostBehavior,
+    pub position: Position,
+    pub movement_state: MovementState,
+    pub movable: Movable,
+    pub sprite: Renderable,
+    pub directional_animated: DirectionalAnimated,
+    pub entity_type: EntityType,
+    pub collider: Collider,
+    pub ghost_collider: GhostCollider,
+}
+
 #[derive(Resource)]
 pub struct GlobalState {
     pub exit: bool,

src/systems/ghost.rs

@@ -0,0 +1,77 @@
+use bevy_ecs::system::{Query, Res};
+use rand::prelude::*;
+use smallvec::SmallVec;
+
+use crate::{
+    entity::direction::Direction,
+    map::builder::Map,
+    systems::{
+        components::{DeltaTime, EntityType, GhostBehavior, GhostType},
+        movement::{Movable, Position},
+    },
+};
+
+/// Ghost AI system that handles randomized movement decisions.
+///
+/// This system runs on all ghosts and makes periodic decisions about
+/// which direction to move in when they reach intersections.
+pub fn ghost_ai_system(
+    map: Res<Map>,
+    delta_time: Res<DeltaTime>,
+    mut ghosts: Query<(&mut GhostBehavior, &mut Movable, &Position, &EntityType, &GhostType)>,
+) {
+    for (mut ghost_behavior, mut movable, position, entity_type, _ghost_type) in ghosts.iter_mut() {
+        // Only process ghosts
+        if *entity_type != EntityType::Ghost {
+            continue;
+        }
+
+        // Update decision timer
+        ghost_behavior.decision_timer += delta_time.0;
+
+        // Check if we should make a new direction decision
+        let should_decide = ghost_behavior.decision_timer >= ghost_behavior.decision_interval;
+        let at_intersection = position.is_at_node();
+
+        if should_decide && at_intersection {
+            choose_random_direction(&map, &mut movable, position);
+            ghost_behavior.decision_timer = 0.0;
+        }
+    }
+}
+
+/// Chooses a random available direction for a ghost at an intersection.
+///
+/// This function mirrors the behavior from the old ghost implementation,
+/// preferring not to reverse direction unless it's the only option.
+fn choose_random_direction(map: &Map, movable: &mut Movable, position: &Position) {
+    let current_node = position.current_node();
+    let intersection = &map.graph.adjacency_list[current_node];
+
+    // Collect all available directions that ghosts can traverse
+    let mut available_directions = SmallVec::<[Direction; 4]>::new();
+    for direction in Direction::DIRECTIONS {
+        if let Some(edge) = intersection.get(direction) {
+            // Check if ghosts can traverse this edge
+            if edge.traversal_flags.contains(crate::entity::graph::TraversalFlags::GHOST) {
+                available_directions.push(direction);
+            }
+        }
+    }
+
+    // Choose a random direction (avoid reversing unless necessary)
+    if !available_directions.is_empty() {
+        let mut rng = SmallRng::from_os_rng();
+
+        // Filter out the opposite direction if possible, but allow it if we have limited options
+        let opposite = movable.current_direction.opposite();
+        let filtered_directions: Vec<_> = available_directions
+            .iter()
+            .filter(|&&dir| dir != opposite || available_directions.len() <= 2)
+            .collect();
+
+        if let Some(&random_direction) = filtered_directions.choose(&mut rng) {
+            movable.requested_direction = Some(*random_direction);
+        }
+    }
+}

src/systems/mod.rs

@@ -10,6 +10,7 @@ pub mod components;
 pub mod control;
 pub mod debug;
 pub mod formatting;
+pub mod ghost;
 pub mod input;
 pub mod item;
 pub mod movement;

src/systems/profiling.rs

@@ -7,7 +7,7 @@ use std::time::Duration;
 use thousands::Separable;
 
 /// The maximum number of systems that can be profiled. Must not be exceeded, or it will panic.
-const MAX_SYSTEMS: usize = 12;
+const MAX_SYSTEMS: usize = 13;
 /// The number of durations to keep in the circular buffer.
 const TIMING_WINDOW_SIZE: usize = 30;