wip

commit 9cba02c71e
Author: Matthew Deville <matthew@stockly.ai>
Date:   Mon Sep 28 21:49:33 2026 +0200

    boids

commit df85367414
Author: Matthew Deville <matthew@stockly.ai>
Date:   Mon Sep 28 12:18:10 2026 +0200

    trunk

commit bcf542f963
Author: Matthew Deville <matthew@stockly.ai>
Date:   Mon Sep 28 10:07:38 2026 +0200

    init biods

.gitignore

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

Cargo.toml

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

Dockerfile

@@ -1,26 +1,70 @@
-FROM rust:1 AS builder
-WORKDIR /usr/src/website
-COPY . .
+# syntax=docker/dockerfile:1
+
+ARG RUST_VERSION=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
-RUN VERSION="$(tomlq -r '.package[] | select(.name == "wasm-bindgen") | .version' Cargo.lock)" \
-    && cargo install wasm-bindgen-cli --version "$VERSION"
+# Install the toolchain declared in rust-toolchain.toml (incl. wasm32 target) in its own layer
+COPY rust-toolchain.toml .
+RUN rustup show active-toolchain || rustup toolchain install
 
-RUN ./build-wasm.sh release
-RUN cargo build --release -p server
+# Prebuilt binaries via cargo-binstall; wasm-bindgen-cli must match the version in Cargo.lock
+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
-RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates curl && rm -rf /var/lib/apt/lists/*
-COPY --from=builder /usr/src/website/target/release/server /usr/local/bin/server
-COPY --from=builder /usr/src/website/static /app/static
+# ---- Planner: compute the dependency recipe ----
+FROM chef AS planner
+COPY . .
+RUN cargo chef prepare --recipe-path recipe.json
+
+# ---- Builder: cook deps (cached), then build the site with trunk ----
+FROM chef AS builder
+COPY --from=planner /app/recipe.json recipe.json
+# 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
+
+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-alpine AS runtime
+
+COPY <<'EOF' /etc/nginx/conf.d/default.conf
+server {
+    listen 3000;
+    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
 
-WORKDIR /app
 EXPOSE 3000
-HEALTHCHECK --interval=30s --timeout=5s --start-period=5s --retries=3 \
-    CMD curl -f http://localhost:3000/health || exit 1
-
-CMD ["server"]

Trunk.toml

@@ -0,0 +1,11 @@
+[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
+	# Server port
+	port = 3000

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

@@ -1,220 +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 {
-                coefficient: 0.5,
-                combine_rule: CoefficientCombine::Average,
-            }
-        ))
-        .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);
-
-    setup_pachinko_rail(&mut commands, &mut meshes, &mut materials);
-
-    if let Ok(window) = window.single() {
-        spawn_screen_edges(&mut commands, &mut meshes, &mut materials, window.size());
-    }
-}
-
-#[derive(Component)]
-pub struct PachinkoRail {
-    pub points: Vec<Vec2>,
-}
-
-fn setup_pachinko_rail(commands: &mut Commands, meshes: &mut Assets<Mesh>, materials: &mut Assets<ColorMaterial>) {
-    // Control points in world space (y up). The spline passes through each one.
-    // Bottom-left entry -> straight up the left wall -> arc over the top -> into the pin zone.
-    let control_points = [
-        Vec2::new(-320.0, -260.0), // rail entry (launch point)
-        Vec2::new(-330.0, -120.0),
-        Vec2::new(-330.0, 60.0),
-        Vec2::new(-320.0, 200.0),
-        Vec2::new(-260.0, 280.0),  // start of the top arc
-        Vec2::new(-160.0, 310.0),
-        Vec2::new(-60.0, 290.0),   // crest, curving down
-        Vec2::new(0.0, 240.0),     // exit: ball drops into the pins here
-    ];
-
-    // Catmull-Rom is a cardinal spline with tension 0.5.
-    // Lower tension = rounder, higher = tighter corners.
-    let curve = CubicCardinalSpline::new(0.5, control_points)
-        .to_curve()
-        .expect("need at least 2 control points");
-    
-    let points: Vec<Vec2> = curve.iter_positions(128).collect();
-
-    commands.spawn((
-        RigidBody::Static,
-        Collider::polyline(points.clone(), None),
-        Mesh2d(meshes.add(Polyline2d::new(points.iter().copied()))),
-        MeshMaterial2d(materials.add(Color::srgb_u8(255, 255, 255))),
-        Transform::from_xyz(0.0, 0.0, 0.0),
-        PachinkoRail { points },
-    ));
-}
-
-#[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)
-    {
-        println!("world_position: {:?}", world_position);
-        
-        commands.spawn((
-            RigidBody::Dynamic,
-            Collider::circle(CIRCLE_RADIUS),
-            LinearVelocity(Vec2::new(-100.0, 200.0)),
-            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();
-            }
-        }
-    }
-}

assets/shaders/sky.wgsl

@@ -0,0 +1,181 @@
+#import bevy_sprite::mesh2d_vertex_output::VertexOutput
+#import bevy_sprite::mesh2d_view_bindings::{globals, view}
+
+// Single-scattering atmosphere (Rayleigh + Mie + ozone) with the sun fixed
+// just above the horizon, plus a thin layer of drifting clouds.
+
+const PI: f32 = 3.14159265;
+
+const PLANET_RADIUS: f32 = 6371000.0;
+const ATMOSPHERE_RADIUS: f32 = 6471000.0;
+const RAYLEIGH_HEIGHT: f32 = 8000.0;
+const MIE_HEIGHT: f32 = 1200.0;
+const CAMERA_ALTITUDE: f32 = 200.0;
+
+const C_RAYLEIGH: vec3<f32> = vec3<f32>(5.802, 13.558, 33.100) * 1e-6;
+const C_MIE: vec3<f32> = vec3<f32>(3.996, 3.996, 3.996) * 1e-6;
+const C_OZONE: vec3<f32> = vec3<f32>(0.650, 1.881, 0.085) * 1e-6;
+const MIE_G: f32 = 0.76;
+
+const VIEW_SAMPLES: i32 = 16;
+const LIGHT_SAMPLES: i32 = 4;
+
+const SUN_INTENSITY: f32 = 20.0;
+const SUN_ANGULAR_RADIUS: f32 = 0.012;
+// Vertical field of view is 2 * atan(FOV_SCALE)
+const FOV_SCALE: f32 = 0.6;
+// Screen height (in NDC) of the horizon line
+const HORIZON_NDC: f32 = -0.55;
+
+fn sun_direction() -> vec3<f32> {
+    // Slightly right of center, ~2 degrees above the horizon
+    return normalize(vec3<f32>(0.25, 0.035, -1.0));
+}
+
+// Near and far distances to a sphere centered at the planet center, or -1
+// when the ray misses.
+fn sphere_hit(origin: vec3<f32>, dir: vec3<f32>, radius: f32) -> vec2<f32> {
+    let b = dot(origin, dir);
+    let c = dot(origin, origin) - radius * radius;
+    let d = b * b - c;
+    if d < 0.0 {
+        return vec2<f32>(-1.0);
+    }
+    let s = sqrt(d);
+    return vec2<f32>(-b - s, -b + s);
+}
+
+fn density(p: vec3<f32>) -> vec3<f32> {
+    let h = max(length(p) - PLANET_RADIUS, 0.0);
+    let ozone = max(0.0, 1.0 - abs(h - 25000.0) / 15000.0);
+    return vec3<f32>(exp(-h / RAYLEIGH_HEIGHT), exp(-h / MIE_HEIGHT), ozone);
+}
+
+fn absorb(optical_depth: vec3<f32>) -> vec3<f32> {
+    return exp(-(optical_depth.x * C_RAYLEIGH
+        + optical_depth.y * C_MIE * 1.1
+        + optical_depth.z * C_OZONE));
+}
+
+fn light_optical_depth(p: vec3<f32>, dir: vec3<f32>) -> vec3<f32> {
+    let len = sphere_hit(p, dir, ATMOSPHERE_RADIUS).y;
+    let step = len / f32(LIGHT_SAMPLES);
+    var depth = vec3<f32>(0.0);
+    for (var i = 0; i < LIGHT_SAMPLES; i++) {
+        depth += density(p + dir * (f32(i) + 0.5) * step) * step;
+    }
+    return depth;
+}
+
+fn phase_rayleigh(c: f32) -> f32 {
+    return 3.0 * (1.0 + c * c) / (16.0 * PI);
+}
+
+fn phase_hg(c: f32, g: f32) -> f32 {
+    let g2 = g * g;
+    return (1.0 - g2) / (4.0 * PI * pow(1.0 + g2 - 2.0 * g * c, 1.5));
+}
+
+// In-scattered light along the view ray; `transmittance` receives the
+// attenuation of whatever lies behind it.
+fn scatter(origin: vec3<f32>, dir: vec3<f32>, sun: vec3<f32>, transmittance: ptr<function, vec3<f32>>) -> vec3<f32> {
+    var len = sphere_hit(origin, dir, ATMOSPHERE_RADIUS).y;
+    let ground = sphere_hit(origin, dir, PLANET_RADIUS);
+    if ground.x > 0.0 {
+        len = ground.x;
+    }
+
+    let c = dot(dir, sun);
+    let phase_r = phase_rayleigh(c);
+    let phase_m = phase_hg(c, MIE_G);
+
+    var depth = vec3<f32>(0.0);
+    var rayleigh = vec3<f32>(0.0);
+    var mie = vec3<f32>(0.0);
+    var prev_t = 0.0;
+    for (var i = 1; i <= VIEW_SAMPLES; i++) {
+        // Quadratic distribution: dense samples near the camera, where the air is thick
+        let f = f32(i) / f32(VIEW_SAMPLES);
+        let t = f * f * len;
+        let step = t - prev_t;
+        let p = origin + dir * (t - 0.5 * step);
+        let local = density(p);
+        depth += local * step;
+
+        let light = absorb(depth + light_optical_depth(p, sun));
+        rayleigh += light * local.x * step;
+        mie += light * local.y * step;
+        prev_t = t;
+    }
+
+    *transmittance = absorb(depth);
+    return (rayleigh * C_RAYLEIGH * phase_r + mie * C_MIE * phase_m) * SUN_INTENSITY;
+}
+
+fn hash(p: vec2<f32>) -> f32 {
+    return fract(sin(dot(p, vec2<f32>(127.1, 311.7))) * 43758.5453);
+}
+
+fn noise(p: vec2<f32>) -> f32 {
+    let i = floor(p);
+    let f = fract(p);
+    let u = f * f * (3.0 - 2.0 * f);
+    return mix(
+        mix(hash(i), hash(i + vec2<f32>(1.0, 0.0)), u.x),
+        mix(hash(i + vec2<f32>(0.0, 1.0)), hash(i + vec2<f32>(1.0, 1.0)), u.x),
+        u.y,
+    );
+}
+
+fn fbm(p: vec2<f32>) -> f32 {
+    var value = 0.0;
+    var amplitude = 0.5;
+    var q = p;
+    for (var i = 0; i < 5; i++) {
+        value += amplitude * noise(q);
+        q *= 2.0;
+        amplitude *= 0.5;
+    }
+    return value;
+}
+
+@fragment
+fn fragment(mesh: VertexOutput) -> @location(0) vec4<f32> {
+    let aspect = view.viewport.z / view.viewport.w;
+    // uv.y is 0 at the top of the quad
+    let ndc = vec2<f32>(mesh.uv.x * 2.0 - 1.0, 1.0 - mesh.uv.y * 2.0);
+    let dir = normalize(vec3<f32>(
+        ndc.x * aspect * FOV_SCALE,
+        (ndc.y - HORIZON_NDC) * FOV_SCALE,
+        -1.0,
+    ));
+
+    let sun = sun_direction();
+    let origin = vec3<f32>(0.0, PLANET_RADIUS + CAMERA_ALTITUDE, 0.0);
+
+    var transmittance: vec3<f32>;
+    var color = scatter(origin, dir, sun, &transmittance);
+
+    let cos_sun = dot(dir, sun);
+    if dir.y > 0.0 {
+        // Sun disc, reddened by the air in front of it
+        let disc = smoothstep(cos(SUN_ANGULAR_RADIUS * 1.2), cos(SUN_ANGULAR_RADIUS * 0.8), cos_sun);
+        color += disc * transmittance * SUN_INTENSITY * 20.0;
+
+        // Clouds on a flat plane, lit by the sunlight that reaches them
+        let p = dir.xz / dir.y * 2.0;
+        let t = globals.time;
+        let clouds = fbm(p + vec2<f32>(t * 0.02, 0.0)) * 0.6
+            + fbm(p * 2.0 + vec2<f32>(t * 0.035, t * 0.008)) * 0.4;
+        let cover = smoothstep(0.5, 0.8, clouds) * smoothstep(0.0, 0.15, dir.y);
+        let sunlight = absorb(light_optical_depth(origin, sun)) * SUN_INTENSITY;
+        let lit = sunlight * (0.04 + phase_hg(cos_sun, 0.6) * 0.3) + color * 0.5;
+        color = mix(color, lit, cover * 0.85);
+    }
+
+    // Exposure tonemap, then dither to hide banding in the gradients
+    color = 1.0 - exp(-color * 2.0);
+    color += (hash(mesh.position.xy) - 0.5) / 255.0;
+
+    return vec4<f32>(color, 1.0);
+}

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;
-
-          cargoLock = fromTOML (builtins.readFile ./Cargo.lock);
-          wasmBindgen = pkgs.lib.findFirst
-            (pkg: pkg.name == "wasm-bindgen")
-            (throw "Could not find wasm-bindgen package")
-            cargoLock.package;
-
-          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=";
-            };
-          };
+          runtimeDeps = with pkgs; [
+            alsa-lib
+            udev
+            vulkan-loader
+            wayland
+            libxkbcommon
+          ];
         in
         {
           devShells.default = pkgs.mkShell {
-            buildInputs = [
+            packages = with pkgs; [
+              pkg-config
               rustToolchain
-              wasm-bindgen-cli
-              pkgs.binaryen
-              pkgs.brotli
-              pkgs.just
+              trunk
             ];
+
+            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/boids.rs

@@ -0,0 +1,218 @@
+use bevy::{platform::collections::HashMap, prelude::*};
+use std::f32::consts::PI;
+
+use crate::{
+    config::ModelConfig,
+    pointer::PointerTarget,
+    spatial_grid::{SpatialGrid, update_spatial_grid},
+};
+
+pub struct BoidsPlugin;
+
+impl Plugin for BoidsPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<SpatialGrid>()
+            .add_systems(Startup, setup)
+            .add_systems(
+                Update,
+                sync_boid_count.run_if(resource_changed::<ModelConfig>),
+            )
+            .add_systems(FixedUpdate, (update_spatial_grid, update_boids).chain());
+    }
+}
+
+#[derive(Component)]
+pub struct Boid {
+    velocity: Vec2,
+}
+
+#[derive(Resource)]
+struct BoidAssets {
+    mesh: Mesh2d,
+    material: MeshMaterial2d<ColorMaterial>,
+}
+
+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;
+
+    // Triangle pointing right
+    let assets = BoidAssets {
+        mesh: Mesh2d(meshes.add(Triangle2d::new(
+            Vec2::new(10.0, 0.0),
+            Vec2::new(-3.0, 3.0),
+            Vec2::new(-3.0, -3.0),
+        ))),
+        material: MeshMaterial2d(materials.add(Color::BLACK)),
+    };
+    spawn_boids(
+        &mut commands,
+        &assets,
+        0..num_boids,
+        num_boids,
+        max_velocity,
+    );
+    commands.insert_resource(assets);
+}
+
+fn spawn_boids(
+    commands: &mut Commands,
+    assets: &BoidAssets,
+    range: std::ops::Range<usize>,
+    num_boids: usize,
+    max_velocity: f32,
+) {
+    let mesh = assets.mesh.clone();
+    let material = assets.material.clone();
+    commands.spawn_batch(range.map(move |n| {
+        let angle = 2.0 * PI / (num_boids as f32) * n as f32;
+        (
+            Boid {
+                velocity: Vec2::from_angle(angle) * max_velocity,
+            },
+            mesh.clone(),
+            material.clone(),
+            Transform::default().rotate(Quat::from_rotation_z(angle)),
+        )
+    }));
+}
+
+/// Spawns or despawns boids so that their count matches `ModelConfig::num_boids`.
+fn sync_boid_count(
+    model_config: Res<ModelConfig>,
+    assets: Option<Res<BoidAssets>>,
+    mut commands: Commands,
+    boids: Query<Entity, With<Boid>>,
+) {
+    let Some(assets) = assets else {
+        return;
+    };
+    let current = boids.iter().len();
+    let target = model_config.num_boids;
+    if target > current {
+        spawn_boids(
+            &mut commands,
+            &assets,
+            current..target,
+            target,
+            model_config.max_velocity,
+        );
+    } else {
+        for entity in boids.iter().take(current - target) {
+            commands.entity(entity).despawn();
+        }
+    }
+}
+
+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>>,
+    grid: Res<SpatialGrid>,
+    pointer: Res<PointerTarget>,
+    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_position) in grid.neighbors(transform.translation.xy()) {
+            if entity == other_entity {
+                continue;
+            }
+            let delta = transform.translation.xy() - other_position;
+            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 {
+                let Ok((_, other_boid, _)) = query.get(other_entity) else {
+                    continue;
+                };
+                avg_speed += other_boid.velocity;
+                avg_pos += other_position;
+                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;
+
+        // Push each boid forward along its current heading
+        let self_force = boid.velocity.normalize_or_zero() * model_config.self_acceleration;
+
+        // Pull towards the mouse cursor or touch point
+        let attraction_force = pointer.0.map_or(Vec2::ZERO, |target| {
+            (target - transform.translation.xy()).normalize_or_zero()
+                * model_config.attraction_force
+        });
+
+        let acceleration = boundary_force
+            + separation_force
+            + alignment_force
+            + cohesion_force
+            + self_force
+            + attraction_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));
+    }
+}

src/config.rs

@@ -0,0 +1,44 @@
+use bevy::prelude::*;
+
+pub struct ConfigPlugin;
+
+impl Plugin for ConfigPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<ModelConfig>()
+            .register_type::<ModelConfig>();
+    }
+}
+
+#[derive(Reflect, Resource)]
+#[reflect(Resource)]
+pub struct ModelConfig {
+    pub num_boids: usize,
+    pub x_bound: f32,
+    pub y_bound: f32,
+    pub max_velocity: f32,
+    pub protected_range: f32,
+    pub visible_range: f32,
+    pub alignment_factor: f32,
+    pub cohesion_factor: f32,
+    pub separation_factor: f32,
+    pub self_acceleration: f32,
+    pub attraction_force: f32,
+}
+
+impl Default for ModelConfig {
+    fn default() -> Self {
+        Self {
+            num_boids: 250,
+            x_bound: 0.75,
+            y_bound: 0.75,
+            max_velocity: 250.0,
+            protected_range: 20.0,
+            visible_range: 230.0,
+            alignment_factor: 0.3,
+            cohesion_factor: 0.2,
+            separation_factor: 500.0,
+            self_acceleration: 100.0,
+            attraction_force: 250.0,
+        }
+    }
+}

src/main.rs

@@ -0,0 +1,34 @@
+mod boids;
+mod config;
+mod pointer;
+mod sky;
+mod spatial_grid;
+mod ui;
+
+use bevy::prelude::*;
+
+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()
+        }))
+        .add_plugins((
+            config::ConfigPlugin,
+            pointer::PointerPlugin,
+            sky::SkyPlugin,
+            boids::BoidsPlugin,
+            ui::ConfigUiPlugin,
+        ))
+        .add_systems(Startup, |mut commands: Commands| {
+            commands.spawn(Camera2d);
+        })
+        .run();
+}

src/pointer.rs

@@ -0,0 +1,28 @@
+use bevy::{prelude::*, window::PrimaryWindow};
+
+pub struct PointerPlugin;
+
+impl Plugin for PointerPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<PointerTarget>()
+            .add_systems(Update, update_pointer_target);
+    }
+}
+
+/// World position of the active touch or mouse cursor, if any.
+#[derive(Resource, Default)]
+pub struct PointerTarget(pub Option<Vec2>);
+
+fn update_pointer_target(
+    window: Single<&Window, With<PrimaryWindow>>,
+    camera: Single<(&Camera, &GlobalTransform)>,
+    touches: Res<Touches>,
+    mut target: ResMut<PointerTarget>,
+) {
+    let (camera, camera_transform) = *camera;
+    // Touch and cursor positions are both in logical window pixels
+    target.0 = touches
+        .first_pressed_position()
+        .or_else(|| window.cursor_position())
+        .and_then(|position| camera.viewport_to_world_2d(camera_transform, position).ok());
+}

src/sky.rs

@@ -0,0 +1,51 @@
+use bevy::{
+    prelude::*,
+    render::render_resource::AsBindGroup,
+    shader::ShaderRef,
+    sprite_render::{Material2d, Material2dPlugin},
+    window::PrimaryWindow,
+};
+
+pub struct SkyPlugin;
+
+impl Plugin for SkyPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_plugins(Material2dPlugin::<SkyMaterial>::default())
+            .add_systems(Startup, setup_sky)
+            .add_systems(Update, fit_sky_to_window);
+    }
+}
+
+/// Animated sky, driven by the global shader time.
+#[derive(Asset, TypePath, AsBindGroup, Clone)]
+struct SkyMaterial {}
+
+impl Material2d for SkyMaterial {
+    fn fragment_shader() -> ShaderRef {
+        "shaders/sky.wgsl".into()
+    }
+}
+
+#[derive(Component)]
+struct Sky;
+
+fn setup_sky(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<SkyMaterial>>,
+) {
+    commands.spawn((
+        Sky,
+        Mesh2d(meshes.add(Rectangle::new(1.0, 1.0))),
+        MeshMaterial2d(materials.add(SkyMaterial {})),
+        // Behind the boids
+        Transform::from_xyz(0.0, 0.0, -10.0),
+    ));
+}
+
+fn fit_sky_to_window(
+    window: Single<&Window, (With<PrimaryWindow>, Changed<Window>)>,
+    mut sky: Single<&mut Transform, With<Sky>>,
+) {
+    sky.scale = window.size().extend(1.0);
+}

src/spatial_grid.rs

@@ -0,0 +1,44 @@
+use bevy::{platform::collections::HashMap, prelude::*};
+
+use crate::{boids::Boid, config::ModelConfig};
+
+#[derive(Resource, Default)]
+pub struct SpatialGrid {
+    pub cell_size: f32,
+    // Maps a grid coordinate (x, y) to the boids (and their positions) in that cell
+    pub cells: HashMap<(i32, i32), Vec<(Entity, Vec2)>>,
+}
+
+impl SpatialGrid {
+    fn cell(&self, position: Vec2) -> (i32, i32) {
+        let cell = (position / self.cell_size).floor();
+        (cell.x as i32, cell.y as i32)
+    }
+
+    /// Entries in the 3x3 block of cells around `position`. With `cell_size` at
+    /// least the search radius, this covers every boid within that radius.
+    pub fn neighbors(&self, position: Vec2) -> impl Iterator<Item = &(Entity, Vec2)> {
+        let (cx, cy) = self.cell(position);
+        (cx - 1..=cx + 1)
+            .flat_map(move |x| (cy - 1..=cy + 1).map(move |y| (x, y)))
+            .filter_map(|key| self.cells.get(&key))
+            .flatten()
+    }
+}
+
+pub fn update_spatial_grid(
+    model_config: Res<ModelConfig>,
+    mut grid: ResMut<SpatialGrid>,
+    boids: Query<(Entity, &Transform), With<Boid>>,
+) {
+    grid.cell_size = model_config
+        .visible_range
+        .max(model_config.protected_range)
+        .max(1.0);
+    grid.cells.clear();
+    for (entity, transform) in &boids {
+        let position = transform.translation.xy();
+        let cell = grid.cell(position);
+        grid.cells.entry(cell).or_default().push((entity, position));
+    }
+}

src/ui.rs

@@ -0,0 +1,146 @@
+use bevy::{prelude::*, reflect::structs::Struct};
+
+use crate::config::ModelConfig;
+
+pub struct ConfigUiPlugin;
+
+impl Plugin for ConfigUiPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, setup_ui).add_systems(
+            Update,
+            (
+                toggle_panel,
+                update_config_labels.run_if(resource_changed::<ModelConfig>),
+            ),
+        );
+    }
+}
+
+/// Editable `ModelConfig` fields and the amount each -/+ click changes them by.
+const CONFIG_FIELDS: &[(&str, f32)] = &[
+    ("num_boids", 5.0),
+    ("x_bound", 0.05),
+    ("y_bound", 0.05),
+    ("max_velocity", 10.0),
+    ("protected_range", 5.0),
+    ("visible_range", 10.0),
+    ("alignment_factor", 0.05),
+    ("cohesion_factor", 0.05),
+    ("separation_factor", 10.0),
+    ("self_acceleration", 5.0),
+    ("attraction_force", 10.0),
+];
+
+#[derive(Component)]
+struct ConfigPanel;
+
+#[derive(Component)]
+struct ConfigLabel(&'static str);
+
+fn read_field(config: &ModelConfig, name: &str) -> String {
+    let field = config.field(name).unwrap();
+    if let Some(v) = field.try_downcast_ref::<f32>() {
+        format!("{v:.2}")
+    } else if let Some(v) = field.try_downcast_ref::<usize>() {
+        v.to_string()
+    } else {
+        unreachable!("unsupported ModelConfig field type for {name}")
+    }
+}
+
+fn step_field(config: &mut ModelConfig, name: &str, delta: f32) {
+    let field = config.field_mut(name).unwrap();
+    if let Some(v) = field.try_downcast_mut::<f32>() {
+        *v = (*v + delta).max(0.0);
+    } else if let Some(v) = field.try_downcast_mut::<usize>() {
+        *v = v.saturating_add_signed(delta as isize);
+    }
+}
+
+fn setup_ui(mut commands: Commands, model_config: Res<ModelConfig>) {
+    let font = TextFont::from_font_size(14.0);
+    commands
+        .spawn((
+            Node {
+                position_type: PositionType::Absolute,
+                top: px(10),
+                left: px(10),
+                padding: UiRect::all(px(8)),
+                display: Display::Grid,
+                // name, -, value, +
+                grid_template_columns: vec![RepeatedGridTrack::auto(4)],
+                row_gap: px(4),
+                column_gap: px(6),
+                align_items: AlignItems::Center,
+                border_radius: BorderRadius::all(px(6)),
+                ..default()
+            },
+            BackgroundColor(Color::srgba(0.0, 0.0, 0.0, 0.6)),
+            Visibility::Hidden,
+            ConfigPanel,
+        ))
+        .with_children(|panel| {
+            for &(name, step) in CONFIG_FIELDS {
+                panel.spawn((Text::new(name), font.clone()));
+                spawn_step_button(panel, "-", name, -step, &font);
+                panel.spawn((
+                    Text::new(read_field(&model_config, name)),
+                    font.clone(),
+                    TextLayout::justify(Justify::Center),
+                    Node {
+                        min_width: px(60),
+                        ..default()
+                    },
+                    ConfigLabel(name),
+                ));
+                spawn_step_button(panel, "+", name, step, &font);
+            }
+        });
+}
+
+fn spawn_step_button(
+    parent: &mut ChildSpawnerCommands,
+    label: &str,
+    field: &'static str,
+    delta: f32,
+    font: &TextFont,
+) {
+    parent
+        .spawn((
+            Button,
+            Node {
+                width: px(22),
+                height: px(22),
+                justify_content: JustifyContent::Center,
+                align_items: AlignItems::Center,
+                border_radius: BorderRadius::all(px(4)),
+                ..default()
+            },
+            BackgroundColor(Color::srgb(0.25, 0.25, 0.4)),
+            children![(Text::new(label), font.clone())],
+        ))
+        .observe(
+            move |_: On<Pointer<Click>>, mut config: ResMut<ModelConfig>| {
+                step_field(&mut config, field, delta);
+            },
+        );
+}
+
+/// Shows or hides the config panel when M is pressed.
+fn toggle_panel(
+    keys: Res<ButtonInput<KeyCode>>,
+    mut panel: Single<&mut Visibility, With<ConfigPanel>>,
+) {
+    if keys.just_pressed(KeyCode::KeyM) {
+        panel.toggle_visible_hidden();
+    }
+}
+
+fn update_config_labels(
+    model_config: Res<ModelConfig>,
+    mut labels: Query<(&ConfigLabel, &mut Text)>,
+) {
+    for (label, mut text) in &mut labels {
+        text.0 = read_field(&model_config, label.0);
+    }
+}

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

web/style.css

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