Set up server to relay ripples and presence info

client/src/main.ts

@@ -1,4 +1,9 @@
 const canvas = document.querySelector<HTMLCanvasElement>('#canvas')!
+const socket = new WebSocket(`ws://${window.location.hostname}:3000`)
+
+type Message =
+  | { type: 'presence-information', others: number }
+  | { type: 'ripple', position: [number, number], maxRadius: number }
 
 const ctx = canvas.getContext('2d')!
 
@@ -14,24 +19,38 @@ type Particle = {
   maxRadius: number
 }
 
-const createParticle = (position: [number, number], maxRadius: number): Particle => ({
-  position,
-  maxRadius,
-  age: 0,
-})
-
 let state = {
   particles: <Particle[]>[]
 }
 
 type State = typeof state
 
-canvas.addEventListener('mousedown', (e) => {
-  // TODO Normalize x and y coords
-  const particle = createParticle([e.clientX, e.clientY], MAX_RADIUS)
-  state.particles.push(particle)
+const createParticle = (position: [number, number], maxRadius: number): Particle => ({
+  position,
+  maxRadius,
+  age: 0,
 })
 
+const makeRipple = (position: [number, number], radius: number): void => {
+  const particle = createParticle(position, radius)
+  socket.send(JSON.stringify(<Message>{
+    type: 'ripple',
+    position: particle.position,
+    maxRadius: particle.maxRadius,
+  }))
+  state.particles.push(particle)
+}
+
+// event handlers
+
+// create a big ripple when touching the screen
+canvas.addEventListener('mousedown', (e) => {
+  // TODO Normalize x and y coords
+  const radius = MAX_RADIUS
+  makeRipple([e.clientX, e.clientY], radius)
+})
+
+// create a smaller ripple when moving over the screen
 function* minDist(dist: number) {
   let prev: Point
   while (true) {
@@ -50,11 +69,33 @@ const hasSpace = minDist(70)
 canvas.addEventListener('mousemove', (e) => {
   const shouldSpawn = hasSpace.next().value!
   if (shouldSpawn([e.clientX, e.clientY])) {
-    const particle = createParticle([e.clientX, e.clientY], MAX_RADIUS / 3*2)
-    state.particles.push(particle)
+    const radius = MAX_RADIUS / 3*2
+    makeRipple([e.clientX, e.clientY], radius)
   }
 })
 
+// react to incoming websocket messages
+socket.addEventListener('message', (e) => {
+  console.log('Received websocket message', e)
+  if (typeof e.data === 'string') {
+    // TODO: Validate message shape
+    const message = JSON.parse(e.data)
+    if (message?.type === 'presence-information') {
+      const data = <Message & { type: 'presence-information' }>message
+      console.log(`i'm seeing ${data.others} others around the pond`)
+    } else if (message?.type === 'ripple') {
+      const data = <Message & { type: 'ripple' }>message
+      const particle = createParticle(data.position, data.maxRadius)
+      state.particles.push(particle)
+    }
+  } else {
+    console.warn('i received an odd message and i don\'t know what to do with it', e.data)
+  }
+})
+
+// main loop
+
+// update the particles and remove them after a certain time
 const update = (state: State, deltaTime: number): State => ({
   particles: state.particles
     .map(p => ({
@@ -64,6 +105,7 @@ const update = (state: State, deltaTime: number): State => ({
     .filter(p => p.age < MAX_AGE)
 })
 
+// draw particles
 const render = (state: State, ctx: CanvasRenderingContext2D) => {
   ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height)
 
@@ -90,6 +132,7 @@ const loop = () => {
   requestAnimationFrame(loop)
 }
 
+// start everything
 document.addEventListener('DOMContentLoaded', () => {
   canvas.width = canvas.parentElement!.clientWidth
   canvas.height = canvas.parentElement!.clientHeight

server/.gitignore

@@ -0,0 +1,175 @@
+# Based on https://raw.githubusercontent.com/github/gitignore/main/Node.gitignore
+
+# Logs
+
+logs
+_.log
+npm-debug.log_
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+.pnpm-debug.log*
+
+# Caches 
+
+.cache
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+
+report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
+
+# Runtime data
+
+pids
+_.pid
+_.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+
+lib-cov
+
+# Coverage directory used by tools like istanbul
+
+coverage
+*.lcov
+
+# nyc test coverage
+
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+
+bower_components
+
+# node-waf configuration
+
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+
+build/Release
+
+# Dependency directories
+
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+
+web_modules/
+
+# TypeScript cache
+
+*.tsbuildinfo
+
+# Optional npm cache directory
+
+.npm
+
+# Optional eslint cache
+
+.eslintcache
+
+# Optional stylelint cache
+
+.stylelintcache
+
+# Microbundle cache
+
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+
+.node_repl_history
+
+# Output of 'npm pack'
+
+*.tgz
+
+# Yarn Integrity file
+
+.yarn-integrity
+
+# dotenv environment variable files
+
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# parcel-bundler cache (https://parceljs.org/)
+
+.parcel-cache
+
+# Next.js build output
+
+.next
+out
+
+# Nuxt.js build / generate output
+
+.nuxt
+dist
+
+# Gatsby files
+
+# Comment in the public line in if your project uses Gatsby and not Next.js
+
+# https://nextjs.org/blog/next-9-1#public-directory-support
+
+# public
+
+# vuepress build output
+
+.vuepress/dist
+
+# vuepress v2.x temp and cache directory
+
+.temp
+
+# Docusaurus cache and generated files
+
+.docusaurus
+
+# Serverless directories
+
+.serverless/
+
+# FuseBox cache
+
+.fusebox/
+
+# DynamoDB Local files
+
+.dynamodb/
+
+# TernJS port file
+
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+
+.vscode-test
+
+# yarn v2
+
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.yarn/install-state.gz
+.pnp.*
+
+# IntelliJ based IDEs
+.idea
+
+# Finder (MacOS) folder config
+.DS_Store

server/README.md

@@ -0,0 +1,15 @@
+# @compost.party/pond-server
+
+To install dependencies:
+
+```bash
+bun install
+```
+
+To run:
+
+```bash
+bun run index.ts
+```
+
+This project was created using `bun init` in bun v1.0.24. [Bun](https://bun.sh) is a fast all-in-one JavaScript runtime.

server/index.ts

@@ -0,0 +1,65 @@
+import { type ServerWebSocket } from "bun"
+
+type WebsocketData = {
+  clientId: string
+}
+
+type Message =
+  | { type: 'presence-information', others: number }
+  | { type: 'ripple', position: [number, number], maxRadius: number }
+
+const clients: Map<WebsocketData['clientId'], ServerWebSocket<WebsocketData>> = new Map()
+
+const server = Bun.serve<WebsocketData>({
+  fetch(req, server) {
+    // TODO Allow creating private ponds
+    server.upgrade(req, {
+      data: {
+        clientId: crypto.randomUUID()
+      }
+    })
+  },
+  websocket: {
+    open(ws) {
+      // register newly connected client and tell them how many other people are there
+      console.log('Connection opened', ws.data.clientId)
+      clients.set(ws.data.clientId, ws)
+      const enterNotice = JSON.stringify(<Message>{
+        type: 'presence-information',
+        others: clients.size,
+      })
+      for (const [uuid, client] of clients.entries()) {
+        if (uuid !== ws.data.clientId) {
+          client.send(enterNotice, true)
+        }
+      }
+    },
+    message(ws, message) {
+      // broadcast message to all other clients
+      // TODO: Validate message shape
+      const msg = JSON.parse(`${message}`)
+      console.log('Relaying message from', ws.data.clientId, msg)
+      for (const [uuid, client] of clients.entries()) {
+        if (uuid !== ws.data.clientId) {
+          client.send(message)
+        }
+      }
+    },
+    close(ws, code, reason) {
+      // remove client from list of registered clients and tell other clients how many people are there
+      console.log('Connection closed', ws.data.clientId)
+      clients.delete(ws.data.clientId)
+      const leaveNotice = JSON.stringify(<Message>{
+        type: 'presence-information',
+        others: clients.size,
+      })
+      for (const [uuid, client] of clients.entries()) {
+        if (uuid !== ws.data.clientId) {
+          client.send(leaveNotice, true)
+        }
+      }
+    }
+  },
+})
+
+console.log(`Server running on ${server.hostname}:${server.port}`)

server/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "@compost.party/pond-server",
+  "module": "index.ts",
+  "type": "module",
+  "devDependencies": {
+    "@types/bun": "latest"
+  },
+  "peerDependencies": {
+    "typescript": "^5.0.0"
+  }
+}

server/tsconfig.json

@@ -0,0 +1,22 @@
+{
+  "compilerOptions": {
+    "lib": ["ESNext"],
+    "target": "ESNext",
+    "module": "ESNext",
+    "moduleDetection": "force",
+    "jsx": "react-jsx",
+    "allowJs": true,
+
+    /* Bundler mode */
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "verbatimModuleSyntax": true,
+    "noEmit": true,
+
+    /* Linting */
+    "skipLibCheck": true,
+    "strict": true,
+    "noFallthroughCasesInSwitch": true,
+    "forceConsistentCasingInFileNames": true
+  }
+}