wip

.dockerignore

@@ -1 +0,0 @@
-.gitignore

.gitignore

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

Cargo.toml

@@ -1,17 +1,22 @@
-[package]
+[workspace]
-	edition = "2024"
+	members = ["app", "server"]
-	name = "website"
+	resolver = "3"
-	version = "0.1.0"
-
-[dependencies]
-	bevy = { version = "0.19", default-features = false, features = ["2d", "ui"] }
-
-[profile.dev.package."*"]
-	opt-level = 3
 
+# Enable more optimization in the release profile at the cost of compile time.
 [profile.release]
+	# Compile the entire crate as one unit.
+	# Slows compile times, marginal improvements.
 	codegen-units = 1
-	lto = "thin"
+	# Do a second optimization pass over the entire program, including dependencies.
+	# Slows compile times, marginal improvements.
+	lto = true
+
+# Optimize for size in the wasm-release profile to reduce load times and bandwidth usage on web.
+[profile.wasm-release]
+	# Default to release profile values.
+	inherits = "release"
+	# Optimize with size in mind (also try "z", sometimes it is better).
+	# Slightly slows compile times, great improvements to file size and runtime performance.
 	opt-level = "z"
-	panic = "abort"
+	# Strip all debugging information from the binary to slightly reduce file size.
-	strip = true
+	strip = "debuginfo"

Dockerfile

@@ -1,70 +1,21 @@
-# syntax=docker/dockerfile:1
+FROM rust:1 AS builder
+WORKDIR /usr/src/website
+COPY . .
 
-ARG RUST_VERSION=1
+RUN rustup target add wasm32-unknown-unknown
+RUN cargo install wasm-bindgen-cli
+
+RUN ./build-wasm.sh
+RUN cargo build --release -p server
+
+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
 
-# ---- 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 curl ca-certificates \
-    && rm -rf /var/lib/apt/lists/*
-
-# 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
-
-# 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
-
-# ---- 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
-
 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

@@ -1,11 +0,0 @@
-[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.toml

@@ -0,0 +1,12 @@
+[package]
+	edition = "2024"
+	name = "app"
+	version = "0.1.0"
+
+[dependencies]
+	bevy = { version = "0.18", default-features = false, features = [
+		"2d",
+		"keyboard",
+		"web",
+		"webgl2",
+	] }

app/src/main.rs

@@ -0,0 +1,18 @@
+use bevy::prelude::*;
+
+const ALIVE_COLOR: [u8; 4] = [0, 255, 136, 255];
+const DEAD_COLOR: [u8; 4] = [18, 18, 32, 255];
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins.set(WindowPlugin {
+            primary_window: Some(Window {
+                title: "Game of Life".into(),
+                fit_canvas_to_parent: true,
+                canvas: Some("#bevy-canvas".into()),
+                ..default()
+            }),
+            ..default()
+        }))
+        .run();
+}

assets/shaders/sky.wgsl

@@ -1,181 +0,0 @@
-#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

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PROFILE="${1:-wasm-release}"
+
+if [ "$PROFILE" = "dev" ]; then
+    PROFILE_DIR="debug"
+    CARGO_FLAGS=""
+else
+    PROFILE_DIR=$PROFILE
+    CARGO_FLAGS="--profile wasm-release"
+fi
+
+cargo build $CARGO_FLAGS --target wasm32-unknown-unknown -p app
+
+mkdir -p static
+wasm-bindgen --out-name app \
+    --out-dir static \
+    --target web \
+    "target/wasm32-unknown-unknown/$PROFILE_DIR/app.wasm"
+
+# Optimize the WASM file for size
+if [ "$PROFILE" = "wasm-release" ]; then
+    wasm-opt -Oz -o static/app_bg.wasm static/app_bg.wasm
+fi
+
+cp web/index.html static/

flake.lock

@@ -1,30 +1,30 @@
 {
   "nodes": {
-    "flake-parts": {
+    "flake-utils": {
       "inputs": {
-        "nixpkgs-lib": "nixpkgs-lib"
+        "systems": "systems"
       },
       "locked": {
-        "lastModified": 1788450739,
+        "lastModified": 1731533236,
-        "narHash": "sha256-glZLQlzIn1fXH6PazR2iUmTo7kzzyYSshrWhLS9TqCU=",
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "hercules-ci",
+        "owner": "numtide",
-        "repo": "flake-parts",
+        "repo": "flake-utils",
-        "rev": "31729ca8cbdb4fa927b34e5f4353e6a83f39e993",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
         "type": "github"
       },
       "original": {
-        "owner": "hercules-ci",
+        "owner": "numtide",
-        "repo": "flake-parts",
+        "repo": "flake-utils",
         "type": "github"
       }
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1790323409,
+        "lastModified": 1771369470,
-        "narHash": "sha256-VVTPf+Hyd5ebpjBMHmrLMSBIeW6ls48Bqtosj7CNKLA=",
+        "narHash": "sha256-0NBlEBKkN3lufyvFegY4TYv5mCNHbi5OmBDrzihbBMQ=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "e94cb152ed51bd6e24eb4a41f1460252beb52cd2",
+        "rev": "0182a361324364ae3f436a63005877674cf45efb",
         "type": "github"
       },
       "original": {
@@ -34,24 +34,9 @@
         "type": "github"
       }
     },
-    "nixpkgs-lib": {
-      "locked": {
-        "lastModified": 1788057806,
-        "narHash": "sha256-DTQSMxzDWmT0zhguthvegnVkn7CFqGCv4IHCzk5ZUpM=",
-        "owner": "nix-community",
-        "repo": "nixpkgs.lib",
-        "rev": "596e2e3940e09b2abbeb03f75fa1828c57fcd72c",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-community",
-        "repo": "nixpkgs.lib",
-        "type": "github"
-      }
-    },
     "root": {
       "inputs": {
-        "flake-parts": "flake-parts",
+        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs",
         "rust-overlay": "rust-overlay"
       }
@@ -63,11 +48,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1790407471,
+        "lastModified": 1771556776,
-        "narHash": "sha256-M8elY2UShg4ZuLTiRLEHO+ae5xQFp3/ReQdxp/R+1UU=",
+        "narHash": "sha256-zKprqMQDl3xVfhSSYvgru1IGXjFdxryWk+KqK0I20Xk=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "4e9bb05a9ab6c37dc74c22974ebed6e36dc73eb2",
+        "rev": "8b3f46b8a6d17ab46e533a5e3d5b1cc2ff228860",
         "type": "github"
       },
       "original": {
@@ -75,6 +60,21 @@
         "repo": "rust-overlay",
         "type": "github"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -2,59 +2,43 @@
   description = "Bevy WASM website";
 
   inputs = {
-    flake-parts.url = "github:hercules-ci/flake-parts";
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     rust-overlay = {
       url = "github:oxalica/rust-overlay";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    flake-utils.url = "github:numtide/flake-utils";
   };
 
   outputs =
-    inputs@{
+    {
-      flake-parts,
+      self,
       nixpkgs,
       rust-overlay,
+      flake-utils,
       ...
     }:
-    flake-parts.lib.mkFlake { inherit inputs; } {
+    flake-utils.lib.eachDefaultSystem (
-      systems = [
+      system:
-        "x86_64-linux"
-        "aarch64-linux"
-        "x86_64-darwin"
-        "aarch64-darwin"
-      ];
-
-      perSystem =
-        { pkgs, system, ... }:
       let
         overlays = [ (import rust-overlay) ];
-          rustPkgs = import nixpkgs {
+        pkgs = import nixpkgs {
           inherit system overlays;
         };
-          rustToolchain = rustPkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+        rustToolchain = pkgs.rust-bin.stable.latest.default.override {
-          runtimeDeps = with pkgs; [
+          extensions = [ "rust-src" ];
-            alsa-lib
+          targets = [ "wasm32-unknown-unknown" ];
-            udev
+        };
-            vulkan-loader
-            wayland
-            libxkbcommon
-          ];
       in
       {
         devShells.default = pkgs.mkShell {
-            packages = with pkgs; [
+          buildInputs = [
-              pkg-config
             rustToolchain
-              trunk
+            pkgs.wasm-bindgen-cli
+            pkgs.binaryen
+            pkgs.just
           ];
-
-            buildInputs = runtimeDeps;
-
-            shellHook = ''
-              export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.lib.makeLibraryPath runtimeDeps}"
-            '';
-          };
-        };
         };
       }
+    );
+}

justfile

@@ -0,0 +1,35 @@
+# Default: build WASM app for release
+default:
+    just build
+
+# Build the WASM app (default: release)
+build profile="wasm-release":
+    ./build-wasm.sh {{ profile }}
+
+# Build for development (faster compile, no wasm-opt)
+build-dev:
+    ./build-wasm.sh dev
+
+# Build the server binary
+build-server:
+    cargo build --release -p server
+
+# Build everything: WASM app + server
+build-all profile="wasm-release":
+    ./build-wasm.sh {{ profile }}
+    cargo build --release -p server
+
+# Serve the site locally (builds WASM first, then runs server on :3000)
+serve profile="wasm-release":
+    ./build-wasm.sh {{ profile }}
+    cargo run --release -p server
+
+# Development: build WASM (dev profile) and run server with hot reload
+dev:
+    ./build-wasm.sh dev
+    cargo run --release -p server
+
+# Clean build artifacts
+clean:
+    cargo clean
+    rm -rf static/*

rust-toolchain.toml

@@ -1,4 +0,0 @@
-[toolchain]
-channel = "1.98.1"
-targets = ["wasm32-unknown-unknown"]
-components = ["clippy", "rust-analyzer", "rustfmt", "rust-src"]

server/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+	edition = "2024"
+	name = "server"
+	version = "0.1.0"
+
+[dependencies]
+	axum = "0.8"
+	tokio = { version = "1", features = ["full"] }
+	tower-http = { version = "0.6", features = ["fs"] }

server/src/main.rs

@@ -0,0 +1,13 @@
+use axum::{Router, routing::get};
+use tower_http::services::ServeDir;
+
+#[tokio::main]
+async fn main() {
+    let app = Router::new()
+        .route("/health", get(|| async { "OK" }))
+        .fallback_service(ServeDir::new("static"));
+
+    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

@@ -1,218 +0,0 @@
-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

@@ -1,44 +0,0 @@
-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

@@ -1,34 +0,0 @@
-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

@@ -1,28 +0,0 @@
-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

@@ -1,51 +0,0 @@
-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

@@ -1,44 +0,0 @@
-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

@@ -1,146 +0,0 @@
-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

@@ -3,15 +3,33 @@
 
 <head>
     <meta charset="utf-8">
-    <title>Personal website</title>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <link data-trunk rel="copy-dir" href="../assets" />
+    <title>Bevy App</title>
-    <link data-trunk rel="inline" href="style.css" />
+    <style>
-    <link data-trunk rel="rust" data-cargo-no-default-features data-wasm-opt="z" data-wasm-opt-params="--all-features"
+        html,
-        href="../" />
+        body {
+            margin: 0;
+            padding: 0;
+            width: 100%;
+            height: 100%;
+            overflow: hidden;
+            background: #1a1a2e;
+        }
+
+        canvas {
+            width: 100%;
+            height: 100%;
+            display: block;
+        }
+    </style>
 </head>
 
 <body>
-    <canvas id="bevy"></canvas>
+    <canvas id="bevy-canvas"></canvas>
+    <script type="module">
+        import init from './app.js';
+        init();
+    </script>
 </body>
 
 </html>

web/style.css

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