feat: ghosts system

src/game/mod.rs

@@ -14,11 +14,13 @@ use crate::systems::{
     blinking::blinking_system,
     collision::collision_system,
     components::{
-        AudioState, Collider, DeltaTime, DirectionalAnimated, EntityType, GlobalState, ItemBundle, ItemCollider, PacmanCollider,
+        AudioState, Collider, DeltaTime, DirectionalAnimated, EntityType, GhostBehavior, GhostBundle, GhostCollider, GhostType,
-        PlayerBundle, PlayerControlled, RenderDirty, Renderable, ScoreResource,
+        GlobalState, ItemBundle, ItemCollider, PacmanCollider, PlayerBundle, PlayerControlled, RenderDirty, Renderable,
+        ScoreResource,
     },
     control::player_system,
     debug::{debug_render_system, DebugState, DebugTextureResource},
+    ghost::ghost_ai_system,
     input::input_system,
     item::item_system,
     movement::movement_system,
@@ -212,6 +214,7 @@ impl Game {
             (
                 profile("input", input_system),
                 profile("player", player_system),
+                profile("ghost_ai", ghost_ai_system),
                 profile("movement", movement_system),
                 profile("collision", collision_system),
                 profile("item", item_system),
@@ -245,6 +248,9 @@ impl Game {
         // Spawn player
         world.spawn(player);
 
+        // Spawn ghosts
+        Self::spawn_ghosts(&mut world)?;
+
         // Spawn items
         let pellet_sprite = SpriteAtlas::get_tile(world.non_send_resource::<SpriteAtlas>(), "maze/pellet.png")
             .ok_or_else(|| GameError::Texture(TextureError::AtlasTileNotFound("maze/pellet.png".to_string())))?;
@@ -288,6 +294,117 @@ impl Game {
         Ok(Game { world, schedule })
     }
 
+    /// Spawns all four ghosts at their starting positions with appropriate textures.
+    fn spawn_ghosts(world: &mut World) -> GameResult<()> {
+        // Extract the data we need first to avoid borrow conflicts
+        let ghost_start_positions = {
+            let map = world.resource::<Map>();
+            [
+                (GhostType::Blinky, map.start_positions.blinky),
+                (GhostType::Pinky, map.start_positions.pinky),
+                (GhostType::Inky, map.start_positions.inky),
+                (GhostType::Clyde, map.start_positions.clyde),
+            ]
+        };
+
+        for (ghost_type, start_node) in ghost_start_positions {
+            // Create the ghost bundle in a separate scope to manage borrows
+            let ghost = {
+                let atlas = world.non_send_resource::<SpriteAtlas>();
+
+                // Create directional animated textures for the ghost
+                let mut textures = [None, None, None, None];
+                let mut stopped_textures = [None, None, None, None];
+
+                for direction in Direction::DIRECTIONS {
+                    let moving_prefix = match direction {
+                        Direction::Up => "up",
+                        Direction::Down => "down",
+                        Direction::Left => "left",
+                        Direction::Right => "right",
+                    };
+
+                    let moving_tiles = vec![
+                        SpriteAtlas::get_tile(atlas, &format!("ghost/{}/{}_{}.png", ghost_type.as_str(), moving_prefix, "a"))
+                            .ok_or_else(|| {
+                                GameError::Texture(TextureError::AtlasTileNotFound(format!(
+                                    "ghost/{}/{}_{}.png",
+                                    ghost_type.as_str(),
+                                    moving_prefix,
+                                    "a"
+                                )))
+                            })?,
+                        SpriteAtlas::get_tile(atlas, &format!("ghost/{}/{}_{}.png", ghost_type.as_str(), moving_prefix, "b"))
+                            .ok_or_else(|| {
+                                GameError::Texture(TextureError::AtlasTileNotFound(format!(
+                                    "ghost/{}/{}_{}.png",
+                                    ghost_type.as_str(),
+                                    moving_prefix,
+                                    "b"
+                                )))
+                            })?,
+                    ];
+
+                    let stopped_tiles = vec![SpriteAtlas::get_tile(
+                        atlas,
+                        &format!("ghost/{}/{}_{}.png", ghost_type.as_str(), moving_prefix, "a"),
+                    )
+                    .ok_or_else(|| {
+                        GameError::Texture(TextureError::AtlasTileNotFound(format!(
+                            "ghost/{}/{}_{}.png",
+                            ghost_type.as_str(),
+                            moving_prefix,
+                            "a"
+                        )))
+                    })?];
+
+                    textures[direction.as_usize()] = Some(AnimatedTexture::new(moving_tiles, 0.2)?);
+                    stopped_textures[direction.as_usize()] = Some(AnimatedTexture::new(stopped_tiles, 0.1)?);
+                }
+
+                GhostBundle {
+                    ghost_type,
+                    ghost_behavior: GhostBehavior::default(),
+                    position: Position {
+                        node: start_node,
+                        edge_progress: None,
+                    },
+                    movement_state: MovementState::Stopped,
+                    movable: Movable {
+                        speed: ghost_type.base_speed(),
+                        current_direction: Direction::Left,
+                        requested_direction: Some(Direction::Left), // Start with some movement
+                    },
+                    sprite: Renderable {
+                        sprite: SpriteAtlas::get_tile(atlas, &format!("ghost/{}/left_a.png", ghost_type.as_str())).ok_or_else(
+                            || {
+                                GameError::Texture(TextureError::AtlasTileNotFound(format!(
+                                    "ghost/{}/left_a.png",
+                                    ghost_type.as_str()
+                                )))
+                            },
+                        )?,
+                        layer: 0,
+                        visible: true,
+                    },
+                    directional_animated: DirectionalAnimated {
+                        textures,
+                        stopped_textures,
+                    },
+                    entity_type: EntityType::Ghost,
+                    collider: Collider {
+                        size: crate::constants::CELL_SIZE as f32 * 1.375,
+                    },
+                    ghost_collider: GhostCollider,
+                }
+            };
+
+            world.spawn(ghost);
+        }
+
+        Ok(())
+    }
+
     /// Ticks the game state.
     ///
     /// Returns true if the game should exit.

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;