boids

.gitignore

@@ -1,4 +1,3 @@
+dist
 target
-static
-result
 .direnv

Cargo.toml

@@ -1,6 +1,10 @@
-[workspace]
+[package]
-	members = ["app", "server"]
+	edition = "2024"
-	resolver = "3"
+	name = "website"
+	version = "0.1.0"
+
+[dependencies]
+	bevy = { version = "0.19", default-features = false, features = ["2d"] }
 
 [profile.dev.package."*"]
 	opt-level = 3

Dockerfile

@@ -1,26 +1,70 @@
-FROM rust:1 AS builder
+# syntax=docker/dockerfile:1
-WORKDIR /usr/src/website
+
-COPY . .
+ARG RUST_VERSION=1.98.1
+
+# ---- Base: Rust toolchain + build tools ----
+FROM rust:${RUST_VERSION}-slim-bookworm AS chef
+WORKDIR /app
 
 RUN apt-get update \
-    && apt-get install -y --no-install-recommends binaryen brotli yq \
+    && apt-get install -y --no-install-recommends curl ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
-RUN rustup target add wasm32-unknown-unknown
+# Install the toolchain declared in rust-toolchain.toml (incl. wasm32 target) in its own layer
-RUN VERSION="$(tomlq -r '.package[] | select(.name == "wasm-bindgen") | .version' Cargo.lock)" \
+COPY rust-toolchain.toml .
-    && cargo install wasm-bindgen-cli --version "$VERSION"
+RUN rustup show active-toolchain || rustup toolchain install
 
-RUN ./build-wasm.sh release
+# Prebuilt binaries via cargo-binstall; wasm-bindgen-cli must match the version in Cargo.lock
-RUN cargo build --release -p server
+RUN curl -L --proto '=https' --tlsv1.2 -sSf \
+        https://raw.githubusercontent.com/cargo-bins/cargo-binstall/main/install-from-binstall-release.sh | bash \
+    && cargo binstall -y --locked cargo-chef trunk
 
-FROM debian:trixie-slim
+# ---- Planner: compute the dependency recipe ----
-RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates curl && rm -rf /var/lib/apt/lists/*
+FROM chef AS planner
-COPY --from=builder /usr/src/website/target/release/server /usr/local/bin/server
+COPY . .
-COPY --from=builder /usr/src/website/static /app/static
+RUN cargo chef prepare --recipe-path recipe.json
 
-WORKDIR /app
+# ---- Builder: cook deps (cached), then build the site with trunk ----
-EXPOSE 3000
+FROM chef AS builder
-HEALTHCHECK --interval=30s --timeout=5s --start-period=5s --retries=3 \
+COPY --from=planner /app/recipe.json recipe.json
-    CMD curl -f http://localhost:3000/health || exit 1
+# Must match the flags trunk passes to cargo (see web/index.html) to reuse the cache
+RUN cargo chef cook --release --target wasm32-unknown-unknown --no-default-features \
+    --recipe-path recipe.json
 
-CMD ["server"]
+COPY . .
+RUN mkdir -p assets
+RUN --mount=type=cache,target=/root/.cache/trunk \
+    trunk build --release --locked
+
+# ---- Runtime: static files served by nginx ----
+FROM nginx:1.29-alpine AS runtime
+
+COPY <<'EOF' /etc/nginx/conf.d/default.conf
+server {
+    listen 80;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    gzip on;
+    gzip_types application/wasm application/javascript text/css;
+
+    # Bevy expects real 404s for missing assets (Trunk.toml: no_spa = true)
+    location / {
+        try_files $uri $uri/ =404;
+    }
+
+    location ~* \.(wasm|js|css)$ {
+        add_header Cache-Control "public, max-age=31536000, immutable";
+        try_files $uri =404;
+    }
+
+    location = /index.html {
+        add_header Cache-Control "no-cache";
+    }
+}
+EOF
+
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+EXPOSE 80

Trunk.toml

@@ -0,0 +1,9 @@
+[build]
+	dist = "dist"
+	target = "web/index.html"
+
+[serve]
+	# Required in order to receive 404s for missing assets, which is what Bevy expects.
+	no_spa = true
+	# Open a browser tab once the initial build is complete.
+	open = true

app/.cargo/config.toml

@@ -1,2 +0,0 @@
-[build]
-target = "wasm32-unknown-unknown"

app/Cargo.toml

@@ -1,8 +0,0 @@
-[package]
-	edition = "2024"
-	name = "app"
-	version = "0.1.0"
-
-[dependencies]
-	avian2d = "0.7"
-	bevy = { version = "0.19", default-features = false, features = ["2d"] }

app/src/main.rs

@@ -1,176 +0,0 @@
-use avian2d::prelude::*;
-use bevy::{
-    input::common_conditions::input_just_pressed,
-    prelude::*,
-    window::{PrimaryWindow, WindowResized},
-};
-
-fn main() {
-    App::new()
-        .insert_resource(ClearColor(Color::srgb_u8(26, 26, 46)))
-        .add_plugins((
-            DefaultPlugins.set(WindowPlugin {
-                primary_window: Some(Window {
-                    fit_canvas_to_parent: true,
-                    prevent_default_event_handling: false,
-                    canvas: Some("#bevy-canvas".into()),
-                    ..default()
-                }),
-                ..default()
-            }),
-            PhysicsPlugins::default(),
-        ))
-        .insert_resource(Time::<Physics>::default().with_relative_speed(5.0))
-        .insert_resource(DefaultRestitution(
-            Restitution::PERFECTLY_ELASTIC.with_combine_rule(CoefficientCombine::Max),
-        ))
-        .add_systems(Startup, setup)
-        .add_systems(
-            Update,
-            (
-                update_screen_edges,
-                spawn_ball.run_if(input_just_pressed(MouseButton::Left)),
-            ),
-        )
-        .run();
-}
-
-#[derive(Component, Clone, Copy)]
-enum ScreenEdge {
-    Top,
-    Bottom,
-    Left,
-    Right,
-}
-
-fn setup(
-    mut commands: Commands,
-    mut meshes: ResMut<Assets<Mesh>>,
-    mut materials: ResMut<Assets<ColorMaterial>>,
-    window: Query<&Window, With<PrimaryWindow>>,
-) {
-    commands.spawn(Camera2d);
-
-    if let Ok(window) = window.single() {
-        spawn_screen_edges(&mut commands, &mut meshes, &mut materials, window.size());
-    }
-}
-
-#[derive(Component, Clone, Copy)]
-struct Ball;
-
-fn spawn_ball(
-    mouse_button: Res<ButtonInput<MouseButton>>,
-    window: Single<&Window, With<PrimaryWindow>>,
-    camera_query: Single<(&Camera, &GlobalTransform)>,
-    time: Res<Time>,
-    mut commands: Commands,
-    mut meshes: ResMut<Assets<Mesh>>,
-    mut materials: ResMut<Assets<ColorMaterial>>,
-) {
-    const CIRCLE_RADIUS: f32 = 5.0;
-
-    let (camera, camera_transform) = *camera_query;
-    if mouse_button.just_pressed(MouseButton::Left)
-        && let Some(cursor_position) = window.cursor_position()
-        && let Ok(world_position) = camera.viewport_to_world_2d(camera_transform, cursor_position)
-    {
-        commands.spawn((
-            RigidBody::Dynamic,
-            Collider::circle(CIRCLE_RADIUS),
-            LinearVelocity(Vec2::new(time.elapsed_secs().sin(), time.elapsed_secs().cos()) * 100.0),
-            Mesh2d(meshes.add(Circle::new(CIRCLE_RADIUS))),
-            MeshMaterial2d(materials.add(Color::hsl(time.elapsed_secs().sin() * 360.0, 1.0, 0.5))),
-            Transform::from_xyz(world_position.x, world_position.y, 0.0),
-            Ball,
-        ));
-    }
-}
-
-fn spawn_screen_edges(
-    commands: &mut Commands,
-    meshes: &mut Assets<Mesh>,
-    materials: &mut Assets<ColorMaterial>,
-    size: Vec2,
-) {
-    const EDGE_COLOR: Color = Color::srgb_u8(255, 255, 255);
-
-    let material = materials.add(EDGE_COLOR);
-
-    for edge in [
-        ScreenEdge::Top,
-        ScreenEdge::Bottom,
-        ScreenEdge::Left,
-        ScreenEdge::Right,
-    ] {
-        let (collider, transform, rect_size) = edge_shape(edge, size);
-        commands.spawn((
-            RigidBody::Static,
-            collider,
-            transform,
-            edge,
-            Mesh2d(meshes.add(Rectangle::from_size(rect_size))),
-            MeshMaterial2d(material.clone()),
-        ));
-    }
-}
-
-fn edge_shape(edge: ScreenEdge, size: Vec2) -> (Collider, Transform, Vec2) {
-    const EDGE_THICKNESS: f32 = 5.0;
-
-    let half = size / 2.0;
-    let thickness = EDGE_THICKNESS;
-
-    match edge {
-        ScreenEdge::Top => {
-            let rect = Vec2::new(size.x, thickness);
-            (
-                Collider::rectangle(rect.x, rect.y),
-                Transform::from_xyz(0.0, half.y - thickness / 2.0, 0.0),
-                rect,
-            )
-        }
-        ScreenEdge::Bottom => {
-            let rect = Vec2::new(size.x, thickness);
-            (
-                Collider::rectangle(rect.x, rect.y),
-                Transform::from_xyz(0.0, -half.y + thickness / 2.0, 0.0),
-                rect,
-            )
-        }
-        ScreenEdge::Left => {
-            let rect = Vec2::new(thickness, size.y);
-            (
-                Collider::rectangle(rect.x, rect.y),
-                Transform::from_xyz(-half.x + thickness / 2.0, 0.0, 0.0),
-                rect,
-            )
-        }
-        ScreenEdge::Right => {
-            let rect = Vec2::new(thickness, size.y);
-            (
-                Collider::rectangle(rect.x, rect.y),
-                Transform::from_xyz(half.x - thickness / 2.0, 0.0, 0.0),
-                rect,
-            )
-        }
-    }
-}
-
-fn update_screen_edges(
-    mut resized: PopulatedMessageReader<WindowResized>,
-    mut edges: Query<(&ScreenEdge, &mut Collider, &mut Transform, &Mesh2d)>,
-    mut meshes: ResMut<Assets<Mesh>>,
-) {
-    for event in resized.read() {
-        let size = Vec2::new(event.width, event.height);
-        for (edge, mut collider, mut transform, mesh2d) in &mut edges {
-            let (new_collider, new_transform, rect_size) = edge_shape(*edge, size);
-            *collider = new_collider;
-            *transform = new_transform;
-            if let Some(mut mesh) = meshes.get_mut(&mesh2d.0) {
-                *mesh = Rectangle::from_size(rect_size).into();
-            }
-        }
-    }
-}

build-wasm.sh

@@ -1,35 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-PROFILE="${1:-release}"
-
-if [ "$PROFILE" = "dev" ]; then
-    PROFILE_DIR="debug"
-    CARGO_FLAGS="--features=bevy/dynamic_linking"
-else
-    PROFILE_DIR="release"
-    CARGO_FLAGS="--release"
-fi
-
-cargo build $CARGO_FLAGS --target wasm32-unknown-unknown -p app
-
-mkdir -p static
-# Drop stale bindgen / compression outputs from prior builds.
-rm -f static/2dscene*
-
-wasm-bindgen --out-name 2dscene \
-    --out-dir static \
-    --target web \
-    "target/wasm32-unknown-unknown/$PROFILE_DIR/app.wasm"
-
-if [ "$PROFILE" != "dev" ]; then
-    wasm-opt -Oz --all-features -o static/2dscene_bg.wasm static/2dscene_bg.wasm
-
-    # Precompress assets Axum will negotiate via Accept-Encoding.
-    for f in static/2dscene_bg.wasm static/2dscene.js; do
-        gzip -9 -k -f "$f"
-        brotli -q 11 -f -k "$f"
-    done
-fi
-
-cp web/index.html static/

flake.nix

@@ -10,7 +10,8 @@
     };
   };
 
-  outputs = inputs@{
+  outputs =
+    inputs@{
       flake-parts,
       nixpkgs,
       rust-overlay,
@@ -24,43 +25,35 @@
         "aarch64-darwin"
       ];
 
-      perSystem = { pkgs, system, ... }:
+      perSystem =
+        { pkgs, system, ... }:
         let
           overlays = [ (import rust-overlay) ];
           rustPkgs = import nixpkgs {
             inherit system overlays;
           };
           rustToolchain = rustPkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
-
+          runtimeDeps = with pkgs; [
-          cargoLock = fromTOML (builtins.readFile ./Cargo.lock);
+            alsa-lib
-          wasmBindgen = pkgs.lib.findFirst
+            udev
-            (pkg: pkg.name == "wasm-bindgen")
+            vulkan-loader
-            (throw "Could not find wasm-bindgen package")
+            wayland
-            cargoLock.package;
+            libxkbcommon
-
+          ];
-          wasm-bindgen-cli = pkgs.buildWasmBindgenCli rec {
-            src = pkgs.fetchCrate {
-              pname = "wasm-bindgen-cli";
-              version = wasmBindgen.version;
-              hash = "sha256-a7lcXJnnZkYReja+iUO7NqqrWyv3toxnUgQb8s4IS5s=";
-            };
-
-            cargoDeps = pkgs.rustPlatform.fetchCargoVendor {
-              inherit src;
-              inherit (src) pname version;
-              hash = "sha256-R1Tas33Ursy8kqsxguAkG0ZhNed2n5uFTAhw1l2qlLY=";
-            };
-          };
         in
         {
           devShells.default = pkgs.mkShell {
-            buildInputs = [
+            packages = with pkgs; [
+              pkg-config
               rustToolchain
-              wasm-bindgen-cli
+              trunk
-              pkgs.binaryen
-              pkgs.brotli
-              pkgs.just
             ];
+
+            buildInputs = runtimeDeps;
+
+            shellHook = ''
+              export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.lib.makeLibraryPath runtimeDeps}"
+            '';
           };
         };
     };

justfile

@@ -1,35 +0,0 @@
-# List available recipes
-default:
-    @just --list
-
-# Build the Bevy app to WASM (release by default; use `just build dev` for debug)
-build profile="release":
-    ./build-wasm.sh {{profile}}
-
-# Build WASM in debug mode
-build-dev:
-    ./build-wasm.sh dev
-
-# Build the HTTP server (release)
-build-server:
-    cargo build --release -p server
-
-# Build WASM + server for production
-build-all: build build-server
-
-# Run the server (serves ./static on :3000)
-serve:
-    cargo run -p server
-
-# Build WASM then run the server
-run: build-dev serve
-
-# Type-check the workspace
-check:
-    cargo clippy --target wasm32-unknown-unknown -p app
-    cargo clippy --target x86_64-unknown-linux-gnu -p server
-
-# Remove build artifacts
-clean:
-    rm -rf static
-    cargo clean

server/Cargo.toml

@@ -1,9 +0,0 @@
-[package]
-	edition = "2024"
-	name = "server"
-	version = "0.1.0"
-
-[dependencies]
-	axum = "0.8"
-	tokio = { version = "1", features = ["full"] }
-	tower-http = { version = "0.7", features = ["fs"] }

server/src/main.rs

@@ -1,17 +0,0 @@
-use axum::{Router, routing::get};
-use tower_http::services::ServeDir;
-
-#[tokio::main]
-async fn main() {
-    let static_files = ServeDir::new("static")
-        .precompressed_gzip()
-        .precompressed_br();
-
-    let app = Router::new()
-        .route("/health", get(|| async { "OK" }))
-        .fallback_service(static_files);
-
-    println!("Listening on http://0.0.0.0:3000");
-    let listener = tokio::net::TcpListener::bind("0.0.0.0:3000").await.unwrap();
-    axum::serve(listener, app).await.unwrap();
-}

src/main.rs

@@ -0,0 +1,177 @@
+use bevy::{platform::collections::HashMap, prelude::*};
+use std::f32::consts::PI;
+
+#[derive(Reflect, Resource)]
+#[reflect(Resource)]
+struct ModelConfig {
+    num_boids: usize,
+    x_bound: f32,
+    y_bound: f32,
+    max_velocity: f32,
+    protected_range: f32,
+    visible_range: f32,
+    alignment_factor: f32,
+    cohesion_factor: f32,
+    separation_factor: f32,
+}
+
+impl Default for ModelConfig {
+    fn default() -> Self {
+        Self {
+            num_boids: 50,
+            x_bound: 0.7,
+            y_bound: 0.7,
+            max_velocity: 200.0,
+            protected_range: 50.0,
+            visible_range: 150.0,
+            alignment_factor: 0.5,
+            cohesion_factor: 0.5,
+            separation_factor: 200.0,
+        }
+    }
+}
+
+fn main() {
+    App::new()
+        .insert_resource(ClearColor(Color::srgb_u8(26, 26, 46)))
+        .insert_resource(Time::<Fixed>::from_hz(60.0))
+        .add_plugins(DefaultPlugins.set(WindowPlugin {
+            primary_window: Some(Window {
+                fit_canvas_to_parent: true,
+                prevent_default_event_handling: false,
+                canvas: Some("#bevy".into()),
+                ..default()
+            }),
+            ..default()
+        }))
+        .init_resource::<ModelConfig>()
+        .register_type::<ModelConfig>()
+        .add_systems(Startup, setup)
+        .add_systems(FixedUpdate, update_boids)
+        .run();
+}
+
+#[derive(Component)]
+struct Boid {
+    velocity: Vec2,
+}
+
+fn setup(
+    model_config: Res<ModelConfig>,
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<ColorMaterial>>,
+) {
+    let ModelConfig {
+        num_boids,
+        max_velocity,
+        ..
+    } = *model_config;
+
+    commands.spawn(Camera2d);
+
+    // Triangle pointing right
+    let triangle_mesh = Mesh2d(meshes.add(Triangle2d::new(
+        Vec2::new(10.0, 0.0),
+        Vec2::new(-3.0, 3.0),
+        Vec2::new(-3.0, -3.0),
+    )));
+    let triangle_material = MeshMaterial2d(materials.add(Color::WHITE));
+    commands.spawn_batch((0..num_boids).map(move |n| {
+        let angle = 2.0 * PI / (num_boids as f32) * n as f32;
+        (
+            Boid {
+                velocity: Vec2::from_angle(angle) * max_velocity,
+            },
+            triangle_mesh.clone(),
+            triangle_material.clone(),
+            Transform::default().rotate(Quat::from_rotation_z(angle)),
+        )
+    }));
+}
+
+struct Model {
+    separation: Vec2,
+    alignment: Vec2,
+    cohesion: Vec2,
+}
+
+fn update_boids(
+    model_config: Res<ModelConfig>,
+    window: Single<&Window, With<bevy::window::PrimaryWindow>>,
+    time: Res<Time<Fixed>>,
+    mut query: Query<(Entity, &mut Boid, &mut Transform)>,
+) {
+    let dt = time.delta_secs();
+    let x_bound = window.width() * model_config.x_bound;
+    let y_bound = window.height() * model_config.y_bound;
+
+    let mut model_updates = HashMap::new();
+    for (entity, boid, transform) in query.iter() {
+        let mut nb_neighbors: usize = 0;
+        let mut separation = Vec2::new(0.0, 0.0);
+        let mut avg_speed = Vec2::new(0.0, 0.0);
+        let mut avg_pos = Vec2::new(0.0, 0.0);
+        for (other_entity, other_boid, other_transform) in query.iter() {
+            if entity == other_entity {
+                continue;
+            }
+            let delta = transform.translation.xy() - other_transform.translation.xy();
+            let distance = delta.length();
+            if distance < model_config.protected_range {
+                if distance > f32::EPSILON {
+                    let direction = delta / distance;
+                    let strength = 1.0 - distance / model_config.protected_range;
+                    separation += direction * strength;
+                }
+            } else if distance < model_config.visible_range {
+                avg_speed += other_boid.velocity;
+                avg_pos += other_transform.translation.xy();
+                nb_neighbors += 1;
+            }
+        }
+        if nb_neighbors > 0 {
+            avg_speed /= nb_neighbors as f32;
+            avg_pos /= nb_neighbors as f32;
+        }
+        model_updates.insert(
+            entity,
+            Model {
+                separation,
+                alignment: avg_speed - boid.velocity,
+                cohesion: avg_pos - transform.translation.xy(),
+            },
+        );
+    }
+
+    for (entity, mut boid, mut transform) in query.iter_mut() {
+        let mut out_of_bounds_acceleration = Vec2::new(0.0, 0.0);
+        if transform.translation.x < -x_bound / 2.0 {
+            out_of_bounds_acceleration.x = 1.0;
+        } else if transform.translation.x > x_bound / 2.0 {
+            out_of_bounds_acceleration.x = -1.0;
+        }
+
+        if transform.translation.y < -y_bound / 2.0 {
+            out_of_bounds_acceleration.y = 1.0;
+        } else if transform.translation.y > y_bound / 2.0 {
+            out_of_bounds_acceleration.y = -1.0;
+        }
+        let out_of_bounds_acceleration = out_of_bounds_acceleration.normalize_or_zero();
+
+        let model_update = model_updates.get(&entity).unwrap();
+
+        let boundary_force = out_of_bounds_acceleration * model_config.max_velocity;
+        let separation_force = model_update.separation * model_config.separation_factor;
+        let alignment_force = model_update.alignment * model_config.alignment_factor;
+        let cohesion_force = model_update.cohesion * model_config.cohesion_factor;
+
+        let acceleration = boundary_force + separation_force + alignment_force + cohesion_force;
+        boid.velocity += acceleration * dt;
+        boid.velocity = boid.velocity.clamp_length_max(model_config.max_velocity);
+
+        transform.translation.x += boid.velocity.x * dt;
+        transform.translation.y += boid.velocity.y * dt;
+        transform.rotation = Quat::from_rotation_z(boid.velocity.y.atan2(boid.velocity.x));
+    }
+}

web/index.html

@@ -3,29 +3,15 @@
 
 <head>
     <meta charset="utf-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Personal website</title>
-    <title>Personal Website</title>
+    <link data-trunk rel="copy-dir" href="../assets" />
-    <style>
+    <link data-trunk rel="inline" href="style.css" />
-        html,
+    <link data-trunk rel="rust" data-cargo-no-default-features data-wasm-opt="z" data-wasm-opt-params="--all-features"
-        body {
+        href="../" />
-            margin: 0;
-            width: 100%;
-            height: 100%;
-            overflow: hidden;
-        }
-
-        canvas {
-            display: block;
-        }
-    </style>
 </head>
 
 <body>
-    <canvas id="bevy-canvas"></canvas>
+    <canvas id="bevy"></canvas>
-    <script type="module">
-        import init from './2dscene.js';
-        init();
-    </script>
 </body>
 
 </html>

web/style.css

@@ -0,0 +1,11 @@
+* {
+    margin: 0;
+    padding: 0;
+    border: 0;
+}
+
+html,
+body {
+    width: 100%;
+    height: 100%;
+}