ci: add concurrency group to 'wasm' job to prevent concurrent page deployments

Bumps the dependencies group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `actions/checkout` from 4 to 5
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build.yaml

@@ -14,23 +14,23 @@ jobs:
           - os: ubuntu-latest
             target: x86_64-unknown-linux-gnu
             artifact_name: pacman
-            toolchain: 1.88.0
+            toolchain: 1.86.0
           - os: macos-13
             target: x86_64-apple-darwin
             artifact_name: pacman
-            toolchain: 1.88.0
+            toolchain: 1.86.0
           - os: macos-latest
             target: aarch64-apple-darwin
             artifact_name: pacman
-            toolchain: 1.88.0
+            toolchain: 1.86.0
           - os: windows-latest
             target: x86_64-pc-windows-gnu
             artifact_name: pacman.exe
-            toolchain: 1.88.0
+            toolchain: 1.86.0
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Rust Toolchain
         uses: dtolnay/rust-toolchain@master
@@ -64,15 +64,16 @@ jobs:
         run: cargo build --release
 
       - name: Acquire Package Version
-        shell: bash
+        id: get_version
+        shell: bash # required to prevent Windows runners from failing
         run: |
-          PACKAGE_VERSION=$(cargo metadata --format-version 1 --no-deps | jq '.packages[0].version' -r)
-          echo "PACKAGE_VERSION=${PACKAGE_VERSION}" >> $GITHUB_ENV
+          set -euo pipefail # exit on error
+          echo "version=$(cargo metadata --format-version 1 --no-deps | jq '.packages[0].version' -r)" >> $GITHUB_OUTPUT
 
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with:
-          name: "pacman-${{ env.PACKAGE_VERSION }}-${{ matrix.target }}"
+          name: "pacman-${{ steps.get_version.outputs.version }}-${{ matrix.target }}"
           path: ./target/release/${{ matrix.artifact_name }}
           retention-days: 7
           if-no-files-found: error
@@ -83,10 +84,13 @@ jobs:
     permissions:
       pages: write
       id-token: write
+    # concurrency group is used to prevent multiple page deployments from being attempted at the same time
+    concurrency:
+      group: ${{ github.workflow }}-wasm
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Setup Emscripten SDK
         uses: pyodide/setup-emsdk@v15
@@ -98,7 +102,7 @@ jobs:
         uses: dtolnay/rust-toolchain@master
         with:
           target: wasm32-unknown-emscripten
-          toolchain: 1.86.0 # we are unfortunately pinned to 1.86.0 for some reason, bulk-memory-opt related issues
+          toolchain: 1.86.0
 
       - name: Rust Cache
         uses: Swatinem/rust-cache@v2

.github/workflows/coverage.yaml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@master

.github/workflows/tests.yaml

@@ -4,7 +4,7 @@ on: ["push", "pull_request"]
 
 env:
   CARGO_TERM_COLOR: always
-  RUST_TOOLCHAIN: 1.88.0
+  RUST_TOOLCHAIN: 1.86.0
 
 jobs:
   test:
@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@master

.gitignore

@@ -5,3 +5,4 @@ emsdk/
 rust-sdl2-emscripten/
 assets/site/build.css
 tailwindcss-*
+lcov.info

Cargo.lock

@@ -13,9 +13,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.98"
+version = "1.0.99"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e16d2d3311acee920a9eb8d33b8cbc1787ce4a264e85f964c2404b969bdcd487"
+checksum = "b0674a1ddeecb70197781e945de4b3b8ffb61fa939a5597bcf48503737663100"
 
 [[package]]
 name = "autocfg"
@@ -79,9 +79,9 @@ dependencies = [
 
 [[package]]
 name = "glam"
-version = "0.30.4"
+version = "0.30.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "50a99dbe56b72736564cfa4b85bf9a33079f16ae8b74983ab06af3b1a3696b11"
+checksum = "f2d1aab06663bdce00d6ca5e5ed586ec8d18033a771906c993a1e3755b368d85"
 
 [[package]]
 name = "hashbrown"
@@ -89,6 +89,12 @@ version = "0.15.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5971ac85611da7067dbfcabef3c70ebb5606018acd9e2a3903a0da507521e0d5"
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "indexmap"
 version = "2.10.0"
@@ -122,9 +128,9 @@ checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
 
 [[package]]
 name = "libc"
-version = "0.2.174"
+version = "0.2.175"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
+checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
 
 [[package]]
 name = "log"
@@ -194,7 +200,9 @@ dependencies = [
  "serde_json",
  "smallvec",
  "spin_sleep",
- "thiserror 1.0.69",
+ "strum",
+ "strum_macros",
+ "thiserror",
  "tracing",
  "tracing-error",
  "tracing-subscriber",
@@ -212,7 +220,7 @@ dependencies = [
  "integer-sqrt",
  "num-traits",
  "rustc-hash",
- "thiserror 2.0.12",
+ "thiserror",
 ]
 
 [[package]]
@@ -372,9 +380,9 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.141"
+version = "1.0.142"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30b9eff21ebe718216c6ec64e1d9ac57087aad11efc64e32002bce4a0d4c03d3"
+checksum = "030fedb782600dcbd6f02d479bf0d817ac3bb40d644745b769d6a96bc3afc5a7"
 dependencies = [
  "itoa",
  "memchr",
@@ -406,6 +414,24 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "strum"
+version = "0.27.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af23d6f6c1a224baef9d3f61e287d2761385a5b88fdab4eb4c6f11aeb54c4bcf"
+
+[[package]]
+name = "strum_macros"
+version = "0.27.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7695ce3845ea4b33927c055a39dc438a45b059f7c1b3d91d38d10355fb8cbca7"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.104"
@@ -417,33 +443,13 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "thiserror"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
-dependencies = [
- "thiserror-impl 1.0.69",
-]
-
 [[package]]
 name = "thiserror"
 version = "2.0.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "567b8a2dae586314f7be2a752ec7474332959c6460e02bde30d702a66d488708"
 dependencies = [
- "thiserror-impl 2.0.12",
-]
-
-[[package]]
-name = "thiserror-impl"
-version = "1.0.69"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
+ "thiserror-impl",
 ]
 
 [[package]]

Cargo.toml

@@ -15,12 +15,14 @@ spin_sleep = "1.3.2"
 rand = { version = "0.9.2", default-features = false, features = ["small_rng", "os_rng"] }
 pathfinding = "4.14"
 once_cell = "1.21.3"
-thiserror = "1.0"
+thiserror = "2.0"
 anyhow = "1.0"
-glam = { version = "0.30.4", features = [] }
+glam = { version = "0.30.5", features = [] }
 serde = { version = "1.0.219", features = ["derive"] }
-serde_json = "1.0.141"
+serde_json = "1.0.142"
 smallvec = "1.15.1"
+strum = "0.27.2"
+strum_macros = "0.27.2"
 
 [profile.release]
 lto = true
@@ -54,4 +56,4 @@ x86_64-apple-darwin = { triplet = "x64-osx" }
 aarch64-apple-darwin = { triplet = "arm64-osx" }
 
 [target.'cfg(target_os = "emscripten")'.dependencies]
-libc = "0.2.16"
+libc = "0.2.175"

README.md

@@ -72,6 +72,8 @@ I wanted to hit a log of goals and features, making it a 'perfect' project that
 
 Since this project is still in progress, I'm only going to cover non-obvious build details. By reading the code, build scripts, and copying the online build workflows, you should be able to replicate the build process.
 
+- We use rustc 1.86.0 for the build, due to bulk-memory-opt related issues on wasm32-unknown-emscripten.
+  - Technically, we could probably use stable or even nightly on desktop targets, but using different versions for different targets is a pain, mainly because of clippy warnings changing between versions.
 - Install `cargo-vcpkg` with `cargo install cargo-vcpkg`, then run `cargo vcpkg build` to build the requisite dependencies via vcpkg.
 - For the WASM build, you need to have the Emscripten SDK cloned; you can do so with `git clone https://github.com/emscripten-core/emsdk.git`
   - The first time you clone, you'll need to install the appropriate SDK version with `./emsdk install 3.1.43` and then activate it with `./emsdk activate 3.1.43`. On Windows, use `./emsdk/emsdk.ps1` instead.

rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+# we are unfortunately pinned to 1.86.0 for some reason, bulk-memory-opt related issues on wasm32-unknown-emscripten
+channel = "1.86.0"
+components = ["rustfmt", "llvm-tools-preview", "clippy"]

src/entity/collision.rs

@@ -0,0 +1,128 @@
+use smallvec::SmallVec;
+use std::collections::HashMap;
+
+use crate::entity::traversal::Position;
+
+/// Trait for entities that can participate in collision detection.
+pub trait Collidable {
+    /// Returns the current position of this entity.
+    fn position(&self) -> Position;
+
+    /// Checks if this entity is colliding with another entity.
+    #[allow(dead_code)]
+    fn is_colliding_with(&self, other: &dyn Collidable) -> bool {
+        positions_overlap(&self.position(), &other.position())
+    }
+}
+
+/// System for tracking entities by their positions for efficient collision detection.
+#[derive(Default)]
+pub struct CollisionSystem {
+    /// Maps node IDs to lists of entity IDs that are at that node
+    node_entities: HashMap<usize, Vec<EntityId>>,
+    /// Maps entity IDs to their current positions
+    entity_positions: HashMap<EntityId, Position>,
+    /// Next available entity ID
+    next_id: EntityId,
+}
+
+/// Unique identifier for an entity in the collision system
+pub type EntityId = u32;
+
+impl CollisionSystem {
+    /// Registers an entity with the collision system and returns its ID
+    pub fn register_entity(&mut self, position: Position) -> EntityId {
+        let id = self.next_id;
+        self.next_id += 1;
+
+        self.entity_positions.insert(id, position);
+        self.update_node_entities(id, position);
+
+        id
+    }
+
+    /// Updates an entity's position
+    pub fn update_position(&mut self, entity_id: EntityId, new_position: Position) {
+        if let Some(old_position) = self.entity_positions.get(&entity_id) {
+            // Remove from old nodes
+            self.remove_from_nodes(entity_id, *old_position);
+        }
+
+        // Update position and add to new nodes
+        self.entity_positions.insert(entity_id, new_position);
+        self.update_node_entities(entity_id, new_position);
+    }
+
+    /// Removes an entity from the collision system
+    #[allow(dead_code)]
+    pub fn remove_entity(&mut self, entity_id: EntityId) {
+        if let Some(position) = self.entity_positions.remove(&entity_id) {
+            self.remove_from_nodes(entity_id, position);
+        }
+    }
+
+    /// Gets all entity IDs at a specific node
+    pub fn entities_at_node(&self, node: usize) -> &[EntityId] {
+        self.node_entities.get(&node).map(|v| v.as_slice()).unwrap_or(&[])
+    }
+
+    /// Gets all entity IDs that could collide with an entity at the given position
+    pub fn potential_collisions(&self, position: &Position) -> Vec<EntityId> {
+        let mut collisions = Vec::new();
+        let nodes = get_nodes(position);
+
+        for node in nodes {
+            collisions.extend(self.entities_at_node(node));
+        }
+
+        // Remove duplicates
+        collisions.sort_unstable();
+        collisions.dedup();
+        collisions
+    }
+
+    /// Updates the node_entities map when an entity's position changes
+    fn update_node_entities(&mut self, entity_id: EntityId, position: Position) {
+        let nodes = get_nodes(&position);
+        for node in nodes {
+            self.node_entities.entry(node).or_default().push(entity_id);
+        }
+    }
+
+    /// Removes an entity from all nodes it was previously at
+    fn remove_from_nodes(&mut self, entity_id: EntityId, position: Position) {
+        let nodes = get_nodes(&position);
+        for node in nodes {
+            if let Some(entities) = self.node_entities.get_mut(&node) {
+                entities.retain(|&id| id != entity_id);
+                if entities.is_empty() {
+                    self.node_entities.remove(&node);
+                }
+            }
+        }
+    }
+}
+
+/// Checks if two positions overlap (entities are at the same location).
+fn positions_overlap(a: &Position, b: &Position) -> bool {
+    let a_nodes = get_nodes(a);
+    let b_nodes = get_nodes(b);
+
+    // Check if any nodes overlap
+    a_nodes.iter().any(|a_node| b_nodes.contains(a_node))
+
+    // TODO: More complex overlap detection, the above is a simple check, but it could become an early filter for more precise calculations later
+}
+
+/// Gets all nodes that an entity is currently at or between.
+fn get_nodes(pos: &Position) -> SmallVec<[usize; 2]> {
+    let mut nodes = SmallVec::new();
+    match pos {
+        Position::AtNode(node) => nodes.push(*node),
+        Position::BetweenNodes { from, to, .. } => {
+            nodes.push(*from);
+            nodes.push(*to);
+        }
+    }
+    nodes
+}

src/entity/ghost.rs

@@ -9,10 +9,13 @@ use rand::prelude::*;
 use smallvec::SmallVec;
 use tracing::error;
 
-use crate::entity::direction::Direction;
-use crate::entity::graph::{Edge, EdgePermissions, Graph, NodeId};
-use crate::entity::r#trait::Entity;
-use crate::entity::traversal::Traverser;
+use crate::entity::{
+    collision::Collidable,
+    direction::Direction,
+    graph::{Edge, EdgePermissions, Graph, NodeId},
+    r#trait::Entity,
+    traversal::Traverser,
+};
 use crate::texture::animated::AnimatedTexture;
 use crate::texture::directional::DirectionalAnimatedTexture;
 use crate::texture::sprite::SpriteAtlas;
@@ -245,3 +248,9 @@ impl Ghost {
         }
     }
 }
+
+impl Collidable for Ghost {
+    fn position(&self) -> crate::entity::traversal::Position {
+        self.traverser.position
+    }
+}

src/entity/item.rs

@@ -0,0 +1,115 @@
+use crate::{
+    constants,
+    entity::{collision::Collidable, graph::Graph},
+    error::EntityError,
+    texture::sprite::{Sprite, SpriteAtlas},
+};
+use sdl2::render::{Canvas, RenderTarget};
+use strum_macros::{EnumCount, EnumIter};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ItemType {
+    Pellet,
+    Energizer,
+    #[allow(dead_code)]
+    Fruit {
+        kind: FruitKind,
+    },
+}
+
+impl ItemType {
+    pub fn get_score(self) -> u32 {
+        match self {
+            ItemType::Pellet => 10,
+            ItemType::Energizer => 50,
+            ItemType::Fruit { kind } => kind.get_score(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, EnumIter, EnumCount)]
+#[allow(dead_code)]
+pub enum FruitKind {
+    Apple,
+    Strawberry,
+    Orange,
+    Melon,
+    Bell,
+    Key,
+    Galaxian,
+}
+
+impl FruitKind {
+    #[allow(dead_code)]
+    pub fn index(self) -> u8 {
+        match self {
+            FruitKind::Apple => 0,
+            FruitKind::Strawberry => 1,
+            FruitKind::Orange => 2,
+            FruitKind::Melon => 3,
+            FruitKind::Bell => 4,
+            FruitKind::Key => 5,
+            FruitKind::Galaxian => 6,
+        }
+    }
+
+    pub fn get_score(self) -> u32 {
+        match self {
+            FruitKind::Apple => 100,
+            FruitKind::Strawberry => 300,
+            FruitKind::Orange => 500,
+            FruitKind::Melon => 700,
+            FruitKind::Bell => 1000,
+            FruitKind::Key => 2000,
+            FruitKind::Galaxian => 3000,
+        }
+    }
+}
+
+pub struct Item {
+    pub node_index: usize,
+    pub item_type: ItemType,
+    pub sprite: Sprite,
+    pub collected: bool,
+}
+
+impl Item {
+    pub fn new(node_index: usize, item_type: ItemType, sprite: Sprite) -> Self {
+        Self {
+            node_index,
+            item_type,
+            sprite,
+            collected: false,
+        }
+    }
+
+    pub fn is_collected(&self) -> bool {
+        self.collected
+    }
+
+    pub fn collect(&mut self) {
+        self.collected = true;
+    }
+
+    pub fn get_score(&self) -> u32 {
+        self.item_type.get_score()
+    }
+
+    pub fn render<T: RenderTarget>(&self, canvas: &mut Canvas<T>, atlas: &mut SpriteAtlas, graph: &Graph) -> anyhow::Result<()> {
+        if !self.collected {
+            let node = graph
+                .get_node(self.node_index)
+                .ok_or(EntityError::NodeNotFound(self.node_index))?;
+            let position = node.position + constants::BOARD_PIXEL_OFFSET.as_vec2();
+            self.sprite.render(canvas, atlas, position)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl Collidable for Item {
+    fn position(&self) -> crate::entity::traversal::Position {
+        crate::entity::traversal::Position::AtNode(self.node_index)
+    }
+}

src/entity/mod.rs

@@ -1,6 +1,8 @@
+pub mod collision;
 pub mod direction;
 pub mod ghost;
 pub mod graph;
+pub mod item;
 pub mod pacman;
 pub mod r#trait;
 pub mod traversal;

src/entity/pacman.rs

@@ -4,10 +4,13 @@
 //! animation, and rendering. Pac-Man moves through the game graph using
 //! a traverser and displays directional animated textures.
 
-use crate::entity::direction::Direction;
-use crate::entity::graph::{Edge, EdgePermissions, Graph, NodeId};
-use crate::entity::r#trait::Entity;
-use crate::entity::traversal::Traverser;
+use crate::entity::{
+    collision::Collidable,
+    direction::Direction,
+    graph::{Edge, EdgePermissions, Graph, NodeId},
+    r#trait::Entity,
+    traversal::Traverser,
+};
 use crate::texture::animated::AnimatedTexture;
 use crate::texture::directional::DirectionalAnimatedTexture;
 use crate::texture::sprite::SpriteAtlas;
@@ -125,3 +128,9 @@ impl Pacman {
         }
     }
 }
+
+impl Collidable for Pacman {
+    fn position(&self) -> crate::entity::traversal::Position {
+        self.traverser.position
+    }
+}

src/game.rs

@@ -17,7 +17,9 @@ use crate::{
     audio::Audio,
     constants::{CELL_SIZE, RAW_BOARD},
     entity::{
+        collision::{Collidable, CollisionSystem, EntityId},
         ghost::{Ghost, GhostType},
+        item::Item,
         pacman::Pacman,
         r#trait::Entity,
     },
@@ -37,8 +39,15 @@ pub struct Game {
     pub map: Map,
     pub pacman: Pacman,
     pub ghosts: Vec<Ghost>,
+    pub items: Vec<Item>,
     pub debug_mode: bool,
 
+    // Collision system
+    collision_system: CollisionSystem,
+    pacman_id: EntityId,
+    ghost_ids: Vec<EntityId>,
+    item_ids: Vec<EntityId>,
+
     // Rendering resources
     atlas: SpriteAtlas,
     map_texture: AtlasTile,
@@ -87,6 +96,9 @@ impl Game {
         let audio = Audio::new();
         let pacman = Pacman::new(&map.graph, pacman_start_node, &atlas)?;
 
+        // Generate items (pellets and energizers)
+        let items = map.generate_items(&atlas)?;
+
         // Create ghosts at random positions
         let mut ghosts = Vec::new();
         let ghost_types = [GhostType::Blinky, GhostType::Pinky, GhostType::Inky, GhostType::Clyde];
@@ -104,12 +116,37 @@ impl Game {
             ghosts.push(ghost);
         }
 
+        // Initialize collision system
+        let mut collision_system = CollisionSystem::default();
+
+        // Register Pac-Man
+        let pacman_id = collision_system.register_entity(pacman.position());
+
+        // Register items
+        let mut item_ids = Vec::new();
+        for item in &items {
+            let item_id = collision_system.register_entity(item.position());
+            item_ids.push(item_id);
+        }
+
+        // Register ghosts
+        let mut ghost_ids = Vec::new();
+        for ghost in &ghosts {
+            let ghost_id = collision_system.register_entity(ghost.position());
+            ghost_ids.push(ghost_id);
+        }
+
         Ok(Game {
             score: 0,
             map,
             pacman,
             ghosts,
+            items,
             debug_mode: false,
+            collision_system,
+            pacman_id,
+            ghost_ids,
+            item_ids,
             map_texture,
             text_texture,
             audio,
@@ -146,6 +183,9 @@ impl Game {
 
         self.pacman = Pacman::new(&self.map.graph, pacman_start_node, &self.atlas)?;
 
+        // Reset items
+        self.items = self.map.generate_items(&self.atlas)?;
+
         // Randomize ghost positions
         let ghost_types = [GhostType::Blinky, GhostType::Pinky, GhostType::Inky, GhostType::Clyde];
         let mut rng = SmallRng::from_os_rng();
@@ -155,6 +195,26 @@ impl Game {
             *ghost = Ghost::new(&self.map.graph, random_node, ghost_types[i], &self.atlas)?;
         }
 
+        // Reset collision system
+        self.collision_system = CollisionSystem::default();
+
+        // Re-register Pac-Man
+        self.pacman_id = self.collision_system.register_entity(self.pacman.position());
+
+        // Re-register items
+        self.item_ids.clear();
+        for item in &self.items {
+            let item_id = self.collision_system.register_entity(item.position());
+            self.item_ids.push(item_id);
+        }
+
+        // Re-register ghosts
+        self.ghost_ids.clear();
+        for ghost in &self.ghosts {
+            let ghost_id = self.collision_system.register_entity(ghost.position());
+            self.ghost_ids.push(ghost_id);
+        }
+
         Ok(())
     }
 
@@ -165,6 +225,60 @@ impl Game {
         for ghost in &mut self.ghosts {
             ghost.tick(dt, &self.map.graph);
         }
+
+        // Update collision system positions
+        self.update_collision_positions();
+
+        // Check for collisions
+        self.check_collisions();
+    }
+
+    fn update_collision_positions(&mut self) {
+        // Update Pac-Man's position
+        self.collision_system.update_position(self.pacman_id, self.pacman.position());
+
+        // Update ghost positions
+        for (ghost, &ghost_id) in self.ghosts.iter().zip(&self.ghost_ids) {
+            self.collision_system.update_position(ghost_id, ghost.position());
+        }
+    }
+
+    fn check_collisions(&mut self) {
+        // Check Pac-Man vs Items
+        let potential_collisions = self.collision_system.potential_collisions(&self.pacman.position());
+
+        for entity_id in potential_collisions {
+            if entity_id != self.pacman_id {
+                // Check if this is an item collision
+                if let Some(item_index) = self.find_item_by_id(entity_id) {
+                    let item = &mut self.items[item_index];
+                    if !item.is_collected() {
+                        item.collect();
+                        self.score += item.get_score();
+
+                        // Handle energizer effects
+                        if matches!(item.item_type, crate::entity::item::ItemType::Energizer) {
+                            // TODO: Make ghosts frightened
+                            tracing::info!("Energizer collected! Ghosts should become frightened.");
+                        }
+                    }
+                }
+
+                // Check if this is a ghost collision
+                if let Some(_ghost_index) = self.find_ghost_by_id(entity_id) {
+                    // TODO: Handle Pac-Man being eaten by ghost
+                    tracing::info!("Pac-Man collided with ghost!");
+                }
+            }
+        }
+    }
+
+    fn find_item_by_id(&self, entity_id: EntityId) -> Option<usize> {
+        self.item_ids.iter().position(|&id| id == entity_id)
+    }
+
+    fn find_ghost_by_id(&self, entity_id: EntityId) -> Option<usize> {
+        self.ghost_ids.iter().position(|&id| id == entity_id)
     }
 
     pub fn draw<T: RenderTarget>(&mut self, canvas: &mut Canvas<T>, backbuffer: &mut Texture) -> GameResult<()> {
@@ -174,6 +288,13 @@ impl Game {
                 canvas.clear();
                 self.map.render(canvas, &mut self.atlas, &mut self.map_texture);
 
+                // Render all items
+                for item in &self.items {
+                    if let Err(e) = item.render(canvas, &mut self.atlas, &self.map.graph) {
+                        tracing::error!("Failed to render item: {}", e);
+                    }
+                }
+
                 // Render all ghosts
                 for ghost in &self.ghosts {
                     if let Err(e) = ghost.render(canvas, &mut self.atlas, &self.map.graph) {

src/map/builder.rs

@@ -1,11 +1,12 @@
 //! Map construction and building functionality.
 
-use crate::constants::{MapTile, BOARD_CELL_SIZE, CELL_SIZE};
+use crate::constants::{MapTile, BOARD_CELL_SIZE, CELL_SIZE, RAW_BOARD};
 use crate::entity::direction::Direction;
 use crate::entity::graph::{EdgePermissions, Graph, Node, NodeId};
+use crate::entity::item::{Item, ItemType};
 use crate::map::parser::MapTileParser;
 use crate::map::render::MapRenderer;
-use crate::texture::sprite::{AtlasTile, SpriteAtlas};
+use crate::texture::sprite::{AtlasTile, Sprite, SpriteAtlas};
 use glam::{IVec2, UVec2, Vec2};
 use sdl2::render::{Canvas, RenderTarget};
 use std::collections::{HashMap, VecDeque};
@@ -187,6 +188,44 @@ impl Map {
         MapRenderer::render_map(canvas, atlas, map_texture);
     }
 
+    /// Generates Item entities for pellets and energizers from the parsed map.
+    pub fn generate_items(&self, atlas: &SpriteAtlas) -> GameResult<Vec<Item>> {
+        // Pre-load sprites to avoid repeated texture lookups
+        let pellet_sprite = SpriteAtlas::get_tile(atlas, "maze/pellet.png")
+            .ok_or_else(|| MapError::InvalidConfig("Pellet texture not found".to_string()))?;
+        let energizer_sprite = SpriteAtlas::get_tile(atlas, "maze/energizer.png")
+            .ok_or_else(|| MapError::InvalidConfig("Energizer texture not found".to_string()))?;
+
+        // Pre-allocate with estimated capacity (typical Pac-Man maps have ~240 pellets + 4 energizers)
+        let mut items = Vec::with_capacity(250);
+
+        // Parse the raw board once
+        let parsed_map = MapTileParser::parse_board(RAW_BOARD)?;
+        let map = parsed_map.tiles;
+
+        // Iterate through the map and collect items more efficiently
+        for (x, row) in map.iter().enumerate() {
+            for (y, tile) in row.iter().enumerate() {
+                match tile {
+                    MapTile::Pellet | MapTile::PowerPellet => {
+                        let grid_pos = IVec2::new(x as i32, y as i32);
+                        if let Some(&node_id) = self.grid_to_node.get(&grid_pos) {
+                            let (item_type, sprite) = match tile {
+                                MapTile::Pellet => (ItemType::Pellet, Sprite::new(pellet_sprite)),
+                                MapTile::PowerPellet => (ItemType::Energizer, Sprite::new(energizer_sprite)),
+                                _ => unreachable!(), // We already filtered for these types
+                            };
+                            items.push(Item::new(node_id, item_type, sprite));
+                        }
+                    }
+                    _ => {}
+                }
+            }
+        }
+
+        Ok(items)
+    }
+
     /// Renders a debug visualization with cursor-based highlighting.
     ///
     /// This function provides interactive debugging by highlighting the nearest node

src/texture/sprite.rs

@@ -6,6 +6,27 @@ use sdl2::render::{Canvas, RenderTarget, Texture};
 use serde::Deserialize;
 use std::collections::HashMap;
 
+/// A simple sprite for stationary items like pellets and energizers.
+#[derive(Clone, Debug)]
+pub struct Sprite {
+    pub atlas_tile: AtlasTile,
+}
+
+impl Sprite {
+    pub fn new(atlas_tile: AtlasTile) -> Self {
+        Self { atlas_tile }
+    }
+
+    pub fn render<C: RenderTarget>(&self, canvas: &mut Canvas<C>, atlas: &mut SpriteAtlas, position: glam::Vec2) -> Result<()> {
+        let dest = crate::helpers::centered_with_size(
+            glam::IVec2::new(position.x as i32, position.y as i32),
+            glam::UVec2::new(self.atlas_tile.size.x as u32, self.atlas_tile.size.y as u32),
+        );
+        let mut tile = self.atlas_tile;
+        tile.render(canvas, atlas, dest)
+    }
+}
+
 #[derive(Clone, Debug, Deserialize)]
 pub struct AtlasMapper {
     pub frames: HashMap<String, MapperFrame>,

tests/collision.rs

@@ -0,0 +1,119 @@
+use pacman::entity::collision::{Collidable, CollisionSystem};
+use pacman::entity::traversal::Position;
+
+struct MockCollidable {
+    pos: Position,
+}
+
+impl Collidable for MockCollidable {
+    fn position(&self) -> Position {
+        self.pos
+    }
+}
+
+#[test]
+fn test_is_colliding_with() {
+    let entity1 = MockCollidable {
+        pos: Position::AtNode(1),
+    };
+    let entity2 = MockCollidable {
+        pos: Position::AtNode(1),
+    };
+    let entity3 = MockCollidable {
+        pos: Position::AtNode(2),
+    };
+    let entity4 = MockCollidable {
+        pos: Position::BetweenNodes {
+            from: 1,
+            to: 2,
+            traversed: 0.5,
+        },
+    };
+
+    assert!(entity1.is_colliding_with(&entity2));
+    assert!(!entity1.is_colliding_with(&entity3));
+    assert!(entity1.is_colliding_with(&entity4));
+    assert!(entity3.is_colliding_with(&entity4));
+}
+
+#[test]
+fn test_collision_system_register_and_query() {
+    let mut collision_system = CollisionSystem::default();
+
+    let pos1 = Position::AtNode(1);
+    let entity1 = collision_system.register_entity(pos1);
+
+    let pos2 = Position::BetweenNodes {
+        from: 1,
+        to: 2,
+        traversed: 0.5,
+    };
+    let entity2 = collision_system.register_entity(pos2);
+
+    let pos3 = Position::AtNode(3);
+    let entity3 = collision_system.register_entity(pos3);
+
+    // Test entities_at_node
+    assert_eq!(collision_system.entities_at_node(1), &[entity1, entity2]);
+    assert_eq!(collision_system.entities_at_node(2), &[entity2]);
+    assert_eq!(collision_system.entities_at_node(3), &[entity3]);
+    assert_eq!(collision_system.entities_at_node(4), &[] as &[u32]);
+
+    // Test potential_collisions
+    let mut collisions1 = collision_system.potential_collisions(&pos1);
+    collisions1.sort_unstable();
+    assert_eq!(collisions1, vec![entity1, entity2]);
+
+    let mut collisions2 = collision_system.potential_collisions(&pos2);
+    collisions2.sort_unstable();
+    assert_eq!(collisions2, vec![entity1, entity2]);
+
+    let mut collisions3 = collision_system.potential_collisions(&pos3);
+    collisions3.sort_unstable();
+    assert_eq!(collisions3, vec![entity3]);
+}
+
+#[test]
+fn test_collision_system_update() {
+    let mut collision_system = CollisionSystem::default();
+
+    let entity1 = collision_system.register_entity(Position::AtNode(1));
+
+    assert_eq!(collision_system.entities_at_node(1), &[entity1]);
+    assert_eq!(collision_system.entities_at_node(2), &[] as &[u32]);
+
+    collision_system.update_position(entity1, Position::AtNode(2));
+
+    assert_eq!(collision_system.entities_at_node(1), &[] as &[u32]);
+    assert_eq!(collision_system.entities_at_node(2), &[entity1]);
+
+    collision_system.update_position(
+        entity1,
+        Position::BetweenNodes {
+            from: 2,
+            to: 3,
+            traversed: 0.1,
+        },
+    );
+
+    assert_eq!(collision_system.entities_at_node(1), &[] as &[u32]);
+    assert_eq!(collision_system.entities_at_node(2), &[entity1]);
+    assert_eq!(collision_system.entities_at_node(3), &[entity1]);
+}
+
+#[test]
+fn test_collision_system_remove() {
+    let mut collision_system = CollisionSystem::default();
+
+    let entity1 = collision_system.register_entity(Position::AtNode(1));
+    let entity2 = collision_system.register_entity(Position::AtNode(1));
+
+    assert_eq!(collision_system.entities_at_node(1), &[entity1, entity2]);
+
+    collision_system.remove_entity(entity1);
+
+    assert_eq!(collision_system.entities_at_node(1), &[entity2]);
+
+    collision_system.remove_entity(entity2);
+    assert_eq!(collision_system.entities_at_node(1), &[] as &[u32]);
+}

tests/directional.rs

@@ -52,3 +52,26 @@ fn test_directional_texture_all_directions() {
         assert!(texture.has_direction(*direction));
     }
 }
+
+#[test]
+fn test_directional_texture_stopped() {
+    let mut stopped_textures = [None, None, None, None];
+    stopped_textures[Direction::Up.as_usize()] = Some(mock_animated_texture(1));
+
+    let texture = DirectionalAnimatedTexture::new([None, None, None, None], stopped_textures);
+
+    assert_eq!(texture.stopped_texture_count(), 1);
+    assert!(texture.has_stopped_direction(Direction::Up));
+    assert!(!texture.has_stopped_direction(Direction::Down));
+}
+
+#[test]
+fn test_directional_texture_tick() {
+    let mut textures = [None, None, None, None];
+    textures[Direction::Up.as_usize()] = Some(mock_animated_texture(1));
+    let mut texture = DirectionalAnimatedTexture::new(textures, [None, None, None, None]);
+
+    // This is a bit of a placeholder, since we can't inspect the inner state easily.
+    // We're just ensuring the tick method runs without panicking.
+    texture.tick(0.1);
+}

tests/game.rs

@@ -1,6 +1,9 @@
 use pacman::constants::RAW_BOARD;
 use pacman::map::Map;
 
+mod collision;
+mod item;
+
 #[test]
 fn test_game_map_creation() {
     let map = Map::new(RAW_BOARD).unwrap();

tests/item.rs

@@ -0,0 +1,53 @@
+use glam::U16Vec2;
+use pacman::{
+    entity::{
+        collision::Collidable,
+        item::{FruitKind, Item, ItemType},
+    },
+    texture::sprite::{AtlasTile, Sprite},
+};
+use strum::{EnumCount, IntoEnumIterator};
+
+#[test]
+fn test_item_type_get_score() {
+    assert_eq!(ItemType::Pellet.get_score(), 10);
+    assert_eq!(ItemType::Energizer.get_score(), 50);
+
+    let fruit = ItemType::Fruit { kind: FruitKind::Apple };
+    assert_eq!(fruit.get_score(), 100);
+}
+
+#[test]
+fn test_fruit_kind_increasing_score() {
+    // Build a list of fruit kinds, sorted by their index
+    let mut kinds = FruitKind::iter()
+        .map(|kind| (kind.index(), kind.get_score()))
+        .collect::<Vec<_>>();
+    kinds.sort_unstable_by_key(|(index, _)| *index);
+
+    assert_eq!(kinds.len(), FruitKind::COUNT as usize);
+
+    // Check that the score increases as expected
+    for window in kinds.windows(2) {
+        let ((_, prev), (_, next)) = (window[0], window[1]);
+        assert!(prev < next, "Fruits should have increasing scores, but {prev:?} < {next:?}");
+    }
+}
+
+#[test]
+fn test_item_creation_and_collection() {
+    let atlas_tile = AtlasTile {
+        pos: U16Vec2::new(0, 0),
+        size: U16Vec2::new(16, 16),
+        color: None,
+    };
+    let sprite = Sprite::new(atlas_tile);
+    let mut item = Item::new(0, ItemType::Pellet, sprite);
+
+    assert!(!item.is_collected());
+    assert_eq!(item.get_score(), 10);
+    assert_eq!(item.position().from_node_id(), 0);
+
+    item.collect();
+    assert!(item.is_collected());
+}

tests/map_builder.rs

@@ -1,47 +1,11 @@
 use glam::Vec2;
-use pacman::constants::{BOARD_CELL_SIZE, CELL_SIZE};
+use pacman::constants::{BOARD_CELL_SIZE, CELL_SIZE, RAW_BOARD};
 use pacman::map::Map;
-
-fn create_minimal_test_board() -> [&'static str; BOARD_CELL_SIZE.y as usize] {
-    let mut board = [""; BOARD_CELL_SIZE.y as usize];
-    board[0] = "############################";
-    board[1] = "#............##............#";
-    board[2] = "#.####.#####.##.#####.####.#";
-    board[3] = "#o####.#####.##.#####.####o#";
-    board[4] = "#.####.#####.##.#####.####.#";
-    board[5] = "#..........................#";
-    board[6] = "#.####.##.########.##.####.#";
-    board[7] = "#.####.##.########.##.####.#";
-    board[8] = "#......##....##....##......#";
-    board[9] = "######.##### ## #####.######";
-    board[10] = "     #.##### ## #####.#     ";
-    board[11] = "     #.##    ==    ##.#     ";
-    board[12] = "     #.## ######## ##.#     ";
-    board[13] = "######.## ######## ##.######";
-    board[14] = "T     .   ########   .     T";
-    board[15] = "######.## ######## ##.######";
-    board[16] = "     #.## ######## ##.#     ";
-    board[17] = "     #.##          ##.#     ";
-    board[18] = "     #.## ######## ##.#     ";
-    board[19] = "######.## ######## ##.######";
-    board[20] = "#............##............#";
-    board[21] = "#.####.#####.##.#####.####.#";
-    board[22] = "#.####.#####.##.#####.####.#";
-    board[23] = "#o..##.......X .......##..o#";
-    board[24] = "###.##.##.########.##.##.###";
-    board[25] = "###.##.##.########.##.##.###";
-    board[26] = "#......##....##....##......#";
-    board[27] = "#.##########.##.##########.#";
-    board[28] = "#.##########.##.##########.#";
-    board[29] = "#..........................#";
-    board[30] = "############################";
-    board
-}
+use sdl2::render::Texture;
 
 #[test]
 fn test_map_creation() {
-    let board = create_minimal_test_board();
-    let map = Map::new(board).unwrap();
+    let map = Map::new(RAW_BOARD).unwrap();
 
     assert!(map.graph.node_count() > 0);
     assert!(!map.grid_to_node.is_empty());
@@ -59,8 +23,7 @@ fn test_map_creation() {
 
 #[test]
 fn test_map_starting_positions() {
-    let board = create_minimal_test_board();
-    let map = Map::new(board).unwrap();
+    let map = Map::new(RAW_BOARD).unwrap();
 
     let pacman_pos = map.find_starting_position(0);
     assert!(pacman_pos.is_some());
@@ -73,8 +36,7 @@ fn test_map_starting_positions() {
 
 #[test]
 fn test_map_node_positions() {
-    let board = create_minimal_test_board();
-    let map = Map::new(board).unwrap();
+    let map = Map::new(RAW_BOARD).unwrap();
 
     for (grid_pos, &node_id) in &map.grid_to_node {
         let node = map.graph.get_node(node_id).unwrap();
@@ -84,3 +46,61 @@ fn test_map_node_positions() {
         assert_eq!(node.position, expected_pos);
     }
 }
+
+#[test]
+fn test_generate_items() {
+    use pacman::texture::sprite::{AtlasMapper, MapperFrame, SpriteAtlas};
+    use std::collections::HashMap;
+
+    let map = Map::new(RAW_BOARD).unwrap();
+
+    // Create a minimal atlas for testing
+    let mut frames = HashMap::new();
+    frames.insert(
+        "maze/pellet.png".to_string(),
+        MapperFrame {
+            x: 0,
+            y: 0,
+            width: 8,
+            height: 8,
+        },
+    );
+    frames.insert(
+        "maze/energizer.png".to_string(),
+        MapperFrame {
+            x: 8,
+            y: 0,
+            width: 8,
+            height: 8,
+        },
+    );
+
+    let mapper = AtlasMapper { frames };
+    let texture = unsafe { std::mem::transmute::<usize, Texture<'static>>(0usize) };
+    let atlas = SpriteAtlas::new(texture, mapper);
+
+    let items = map.generate_items(&atlas).unwrap();
+
+    // Verify we have items
+    assert!(!items.is_empty());
+
+    // Count different types
+    let pellet_count = items
+        .iter()
+        .filter(|item| matches!(item.item_type, pacman::entity::item::ItemType::Pellet))
+        .count();
+    let energizer_count = items
+        .iter()
+        .filter(|item| matches!(item.item_type, pacman::entity::item::ItemType::Energizer))
+        .count();
+
+    // Should have both types
+    assert_eq!(pellet_count, 240);
+    assert_eq!(energizer_count, 4);
+
+    // All items should be uncollected initially
+    assert!(items.iter().all(|item| !item.is_collected()));
+
+    // All items should have valid node indices
+    assert!(items.iter().all(|item| item.node_index < map.graph.node_count()));
+}

tests/sprite.rs

@@ -1,4 +1,5 @@
-use pacman::texture::sprite::{AtlasMapper, MapperFrame, SpriteAtlas};
+use glam::U16Vec2;
+use pacman::texture::sprite::{AtlasMapper, AtlasTile, MapperFrame, Sprite, SpriteAtlas};
 use sdl2::pixels::Color;
 use std::collections::HashMap;
 
@@ -76,3 +77,27 @@ fn test_sprite_atlas_color() {
     atlas.set_color(color);
     assert_eq!(atlas.default_color(), Some(color));
 }
+
+#[test]
+fn test_atlas_tile_new_and_with_color() {
+    let pos = U16Vec2::new(10, 20);
+    let size = U16Vec2::new(30, 40);
+    let color = Color::RGB(100, 150, 200);
+
+    let tile = AtlasTile::new(pos, size, None);
+    assert_eq!(tile.pos, pos);
+    assert_eq!(tile.size, size);
+    assert_eq!(tile.color, None);
+
+    let tile_with_color = tile.with_color(color);
+    assert_eq!(tile_with_color.color, Some(color));
+}
+
+#[test]
+fn test_sprite_new() {
+    let atlas_tile = AtlasTile::new(U16Vec2::new(0, 0), U16Vec2::new(16, 16), None);
+    let sprite = Sprite::new(atlas_tile);
+
+    assert_eq!(sprite.atlas_tile.pos, atlas_tile.pos);
+    assert_eq!(sprite.atlas_tile.size, atlas_tile.size);
+}