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Author SHA1 Message Date
Matthew Deville
b0297c53f2 wip 2026-02-22 15:41:34 +01:00
25 changed files with 2146 additions and 2444 deletions

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.gitignore

5
.gitignore vendored
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dist
target
/target
/static
/result
.direnv

3424
Cargo.lock generated

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[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
[workspace]
members = ["app", "server"]
resolver = "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 = true
# Strip all debugging information from the binary to slightly reduce file size.
strip = "debuginfo"

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@ -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"]

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@ -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

12
app/Cargo.toml Normal file
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[package]
edition = "2024"
name = "app"
version = "0.1.0"
[dependencies]
bevy = { version = "0.18", default-features = false, features = [
"2d",
"keyboard",
"web",
"webgl2",
] }

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app/src/main.rs Normal file
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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();
}

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@ -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);
}

27
build-wasm.sh Executable file
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#!/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/

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@ -1,30 +1,30 @@
{
"nodes": {
"flake-parts": {
"flake-utils": {
"inputs": {
"nixpkgs-lib": "nixpkgs-lib"
"systems": "systems"
},
"locked": {
"lastModified": 1788450739,
"narHash": "sha256-glZLQlzIn1fXH6PazR2iUmTo7kzzyYSshrWhLS9TqCU=",
"owner": "hercules-ci",
"repo": "flake-parts",
"rev": "31729ca8cbdb4fa927b34e5f4353e6a83f39e993",
"lastModified": 1731533236,
"narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
"owner": "numtide",
"repo": "flake-utils",
"rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
"type": "github"
},
"original": {
"owner": "hercules-ci",
"repo": "flake-parts",
"owner": "numtide",
"repo": "flake-utils",
"type": "github"
}
},
"nixpkgs": {
"locked": {
"lastModified": 1790323409,
"narHash": "sha256-VVTPf+Hyd5ebpjBMHmrLMSBIeW6ls48Bqtosj7CNKLA=",
"lastModified": 1771369470,
"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,
"narHash": "sha256-M8elY2UShg4ZuLTiRLEHO+ae5xQFp3/ReQdxp/R+1UU=",
"lastModified": 1771556776,
"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",

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@ -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; } {
systems = [
"x86_64-linux"
"aarch64-linux"
"x86_64-darwin"
"aarch64-darwin"
];
perSystem =
{ pkgs, system, ... }:
flake-utils.lib.eachDefaultSystem (
system:
let
overlays = [ (import rust-overlay) ];
rustPkgs = import nixpkgs {
pkgs = import nixpkgs {
inherit system overlays;
};
rustToolchain = rustPkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
runtimeDeps = with pkgs; [
alsa-lib
udev
vulkan-loader
wayland
libxkbcommon
];
rustToolchain = pkgs.rust-bin.stable.latest.default.override {
extensions = [ "rust-src" ];
targets = [ "wasm32-unknown-unknown" ];
};
in
{
devShells.default = pkgs.mkShell {
packages = with pkgs; [
pkg-config
buildInputs = [
rustToolchain
trunk
pkgs.wasm-bindgen-cli
pkgs.binaryen
pkgs.just
];
buildInputs = runtimeDeps;
shellHook = ''
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.lib.makeLibraryPath runtimeDeps}"
'';
};
};
};
}
);
}

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justfile Normal file
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# 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/*

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

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server/Cargo.toml Normal file
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[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"] }

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server/src/main.rs Normal file
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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();
}

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@ -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));
}
}

View file

@ -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,
}
}
}

View file

@ -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();
}

View file

@ -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());
}

View file

@ -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);
}

View file

@ -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));
}
}

146
src/ui.rs
View file

@ -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);
}
}

View file

@ -3,15 +3,33 @@
<head>
<meta charset="utf-8">
<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="../" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Bevy App</title>
<style>
html,
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>

View file

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