// The `type: gesture` requirement widget: draw one stroke on a canvas, // and the stroke becomes the field's value. Mirrors the two house // patterns at once: // // - prosekit-editor.js's hidden-input bridge: the widget writes JSON // into a paired hidden and fires a real bubbling `input` // event, so the Rust side reuses the exact same RwSignal/on:input // wiring every other field kind uses - no bespoke value channel. // - yes.js's lifecycle: mountGesture returns a handle whose stop() // tears everything down (socket, listeners, rAF), because SPA // navigation never unloads the document. // // When a relay URL is given, the widget also speaks the redoal-relay // protocol (ADR-0013 in the redoal repo): announce the stroke, receive // an ack carrying the stroke's gesture key plus the key's own decoded // path - "what the network heard", drawn as a ghost under the stroke // when the key is v2 or later (ADR-0014's ordered turning chain; a v1 // key's histogram decode is a blob and stays hidden) - and receive // echoes of similar strokes other visitors drew, shown as thumbnails. // Everything network is best-effort: no relay, refused connection, or // a dropped socket all degrade to a plain offline drawing input. // // Canvas colors can't come from CSS custom properties (same // constraint yes.js documents), so the widget carries its own copy of // the palette for both themes - any palette change must land here AND // in style/main.css. const THEMES = { dark: { stroke: '#8ec2c0', echo: '#8ec2c0', ghost: 'rgba(255, 255, 255, 0.28)', }, light: { stroke: '#47807e', echo: '#47807e', ghost: 'rgba(29, 29, 27, 0.30)', }, }; const MIN_POINT_DISTANCE = 3; // css px between recorded points const MAX_ECHOES = 8; const RECONNECT_BASE_MS = 1000; const RECONNECT_MAX_MS = 30000; // ── Convergence animation (ink → what the network heard) ────────── // // When the ack lands, a glowing copy of the stroke peels off and // converges point-by-point onto the key's decoded path: a wave of // "being understood" travels from the stroke's start to its end, // and the ghost materializes where the light settles. WebGL point // sprites with additive glow on a dedicated overlay canvas; the 2d // layer underneath never changes its final render, so losing WebGL // (or prefers-reduced-motion) degrades to exactly today's behavior. const CONVERGE_MS = 1500; const CONVERGE_FADE_MS = 450; const CONVERGE_POINTS = 128; const CONVERGE_STAGGER = 0.6; // fraction of the timeline spent on the travelling wave const GLOW_VERT = ` attribute vec2 aFrom; attribute vec2 aTo; attribute float aIndex; uniform float uT; uniform vec2 uResolution; uniform float uDpr; varying float vLife; void main() { float lead = aIndex * ${CONVERGE_STAGGER}; float p = clamp((uT * ${1.0 + CONVERGE_STAGGER} - lead), 0.0, 1.0); float e = p < 0.5 ? 4.0 * p * p * p : 1.0 - pow(-2.0 * p + 2.0, 3.0) / 2.0; vec2 pos = mix(aFrom, aTo, e); vec2 clip = (pos / uResolution) * 2.0 - 1.0; gl_Position = vec4(clip.x, -clip.y, 0.0, 1.0); float pulse = 1.0 + 1.4 * sin(3.14159 * p); gl_PointSize = 9.0 * uDpr * pulse; vLife = p; }`; const GLOW_FRAG = ` precision mediump float; uniform vec3 uColor; uniform float uAlpha; varying float vLife; void main() { vec2 d = gl_PointCoord - 0.5; float fall = exp(-dot(d, d) * 18.0); float breathe = 0.55 + 0.45 * sin(3.14159 * vLife); gl_FragColor = vec4(uColor, 1.0) * (fall * uAlpha * breathe); }`; // Uniform arc-length resample of a pixel-space polyline to n points. function resamplePx(points, n) { if (points.length === 1) return Array(n).fill(points[0]); const dists = [0]; for (let i = 1; i < points.length; i++) { const dx = points[i][0] - points[i - 1][0]; const dy = points[i][1] - points[i - 1][1]; dists.push(dists[i - 1] + Math.hypot(dx, dy)); } const total = dists[dists.length - 1] || 1; const out = []; let seg = 0; for (let i = 0; i < n; i++) { const target = (i / (n - 1)) * total; while (seg < points.length - 2 && dists[seg + 1] < target) seg++; const span = dists[seg + 1] - dists[seg] || 1; const t = (target - dists[seg]) / span; out.push([ points[seg][0] + (points[seg + 1][0] - points[seg][0]) * t, points[seg][1] + (points[seg + 1][1] - points[seg][1]) * t, ]); } return out; } class GestureWidget { constructor(container, hidden, relayUrl) { this.container = container; this.hidden = hidden || null; this.relayUrl = relayUrl || ''; this.ghost = null; this.ownKey = null; this.selected = null; // {key, path, distance} - a place the visitor picked this.seenKeys = new Set(); this.points = []; this.drawing = false; this.stopped = false; this.ws = null; this.reconnectDelay = RECONNECT_BASE_MS; this.reconnectTimer = null; this.pendingAnnounce = null; this.canvas = document.createElement('canvas'); this.canvas.className = 'gesture-canvas'; container.appendChild(this.canvas); // Overlay for the convergence glow; sized with the main canvas, // inert to pointers, empty until an ack arrives. this.glow = document.createElement('canvas'); this.glow.className = 'gesture-glow'; this.glow.style.position = 'absolute'; this.glow.style.pointerEvents = 'none'; if (!container.style.position) container.style.position = 'relative'; container.appendChild(this.glow); this.gl = null; this.animFrame = null; this.converging = false; this.echoes = document.createElement('div'); this.echoes.className = 'gesture-echoes'; this.echoes.setAttribute('role', 'listbox'); this.echoes.setAttribute('aria-label', 'places near your shape'); container.appendChild(this.echoes); this.empty = document.createElement('p'); this.empty.className = 'gesture-empty'; container.appendChild(this.empty); if (this.relayUrl) { this.status = document.createElement('span'); this.status.className = 'gesture-status offline'; this.status.setAttribute('aria-label', 'relay connection'); container.appendChild(this.status); } this._themeQuery = window.matchMedia('(prefers-color-scheme: light)'); this._onTheme = () => this.render(); this._themeQuery.addEventListener('change', this._onTheme); this._onResize = () => { this.sizeCanvas(); this.render(); }; window.addEventListener('resize', this._onResize); this.sizeCanvas(); this._onDown = (e) => this.beginStroke(e); this._onMove = (e) => this.extendStroke(e); this._onUp = (e) => this.endStroke(e); this.canvas.addEventListener('pointerdown', this._onDown); this.canvas.addEventListener('pointermove', this._onMove); this.canvas.addEventListener('pointerup', this._onUp); this.canvas.addEventListener('pointercancel', this._onUp); if (this.relayUrl) this.connect(); } theme() { return this._themeQuery.matches ? THEMES.light : THEMES.dark; } sizeCanvas() { const rect = this.canvas.getBoundingClientRect(); const dpr = window.devicePixelRatio || 1; this.canvas.width = Math.max(1, Math.round(rect.width * dpr)); this.canvas.height = Math.max(1, Math.round(rect.height * dpr)); this.ctx = this.canvas.getContext('2d'); this.ctx.scale(dpr, dpr); this.cssWidth = rect.width; this.cssHeight = rect.height; this.glow.style.left = `${this.canvas.offsetLeft}px`; this.glow.style.top = `${this.canvas.offsetTop}px`; this.glow.style.width = `${rect.width}px`; this.glow.style.height = `${rect.height}px`; this.glow.width = this.canvas.width; this.glow.height = this.canvas.height; this.cancelConvergence(); // buffers are in old pixels } pos(e) { const rect = this.canvas.getBoundingClientRect(); return { x: e.clientX - rect.left, y: e.clientY - rect.top }; } beginStroke(e) { e.preventDefault(); this.canvas.setPointerCapture(e.pointerId); // One stroke only - a new pointerdown replaces the old drawing // (and any ghost from the previous round). this.drawing = true; this.cancelConvergence(); this.ghost = null; this.ownKey = null; this.selected = null; this.seenKeys.clear(); this.echoes.replaceChildren(); this.empty.textContent = ''; this.points = [this.pos(e)]; this.render(); } extendStroke(e) { if (!this.drawing) return; const p = this.pos(e); const last = this.points[this.points.length - 1]; const dx = p.x - last.x, dy = p.y - last.y; if (Math.sqrt(dx * dx + dy * dy) < MIN_POINT_DISTANCE) return; this.points.push(p); this.render(); } endStroke() { if (!this.drawing) return; this.drawing = false; if (this.points.length < 2) return; const normalized = this.normalized(); this.setValue({ points: normalized, key: null }); this.announce(normalized); } // Canvas-frame normalization into the -1..1 square (the relay // re-normalizes around the stroke itself before keying - this // just bounds the payload and keeps the stored value // resolution-independent). normalized() { const half = Math.max(this.cssWidth, this.cssHeight) / 2; const cx = this.cssWidth / 2, cy = this.cssHeight / 2; return this.points.map((p) => [ Math.round(((p.x - cx) / half) * 10000) / 10000, Math.round(((p.y - cy) / half) * 10000) / 10000, ]); } setValue(value) { if (!this.hidden) return; this.hidden.value = JSON.stringify(value); this.hidden.dispatchEvent(new Event('input', { bubbles: true })); } // ── Relay ────────────────────────────────────────────────────── connect() { if (this.stopped) return; let ws; try { ws = new WebSocket(this.relayUrl); } catch { this.scheduleReconnect(); return; } this.ws = ws; ws.addEventListener('open', () => { if (this.stopped) return; this.reconnectDelay = RECONNECT_BASE_MS; this.status?.classList.replace('offline', 'live'); if (this.pendingAnnounce) { ws.send(JSON.stringify({ type: 'announce', points: this.pendingAnnounce })); this.pendingAnnounce = null; } }); ws.addEventListener('message', (e) => this.onMessage(e)); ws.addEventListener('close', () => { this.status?.classList.replace('live', 'offline'); this.ws = null; this.scheduleReconnect(); }); // 'error' is always followed by 'close'; nothing to do here. } scheduleReconnect() { if (this.stopped || this.reconnectTimer) return; this.reconnectTimer = setTimeout(() => { this.reconnectTimer = null; this.connect(); }, this.reconnectDelay); this.reconnectDelay = Math.min(this.reconnectDelay * 2, RECONNECT_MAX_MS); } announce(points) { if (!this.relayUrl) return; if (this.ws && this.ws.readyState === WebSocket.OPEN) { this.ws.send(JSON.stringify({ type: 'announce', points })); } else { this.pendingAnnounce = points; } } onMessage(e) { let msg; try { msg = JSON.parse(e.data); } catch { return; } if (msg.type === 'ack') { this.ownKey = msg.key; // Version nibble is the key's first hex digit. const version = parseInt((msg.key || '0')[0], 16); this.ownGhost = version >= 2 && Array.isArray(msg.path) ? msg.path : null; this.applySelection(); // Places arrive right after the ack; say so if none do. clearTimeout(this.emptyTimer); this.emptyTimer = setTimeout(() => { if (!this.echoes.children.length) this.empty.textContent = msg.empty || 'Nothing kept at this shape yet.'; }, 1500); } else if (msg.type === 'echo' || msg.type === 'place') { if (!msg.key || this.seenKeys.has(msg.key)) return; this.seenKeys.add(msg.key); this.empty.textContent = ''; this.addEchoThumbnail(msg); } // 'error' frames are intentionally silent: the widget is a // form field first, and a rate-limited announce shouldn't // alarm anyone mid-form. } // The key the input carries: the visitor's own, or the place they // picked (selection re-derives the key - the ghost under the // stroke becomes that place's decode, and the answer records both). applySelection() { if (this.points.length < 2) return; const points = this.normalized(); const before = this.ghost; if (this.selected) { this.ghost = this.selected.path; this.setValue({ points, key: this.selected.key, own_key: this.ownKey, selected_from: this.ownKey, selected_distance: this.selected.distance }); } else { this.ghost = this.ownGhost || null; this.setValue({ points, key: this.ownKey }); } if (this.ghost && this.ghost !== before) this.startConvergence(this.ghost); for (const el of this.echoes.children) { el.classList.toggle('selected', !!this.selected && el.dataset.key === this.selected.key); el.setAttribute('aria-selected', String(!!this.selected && el.dataset.key === this.selected.key)); } this.render(); } select(thumb) { const key = thumb.dataset.key; if (this.selected && this.selected.key === key) { this.selected = null; } else { this.selected = { key, path: JSON.parse(thumb.dataset.path), distance: Number(thumb.dataset.distance) }; // The relay counts picks per place for ranking. if (this.ws && this.ws.readyState === WebSocket.OPEN && this.ownKey) { this.ws.send(JSON.stringify({ type: 'select', key, from: this.ownKey, distance: this.selected.distance })); } } this.applySelection(); } addEchoThumbnail(msg) { const thumb = document.createElement('canvas'); thumb.className = 'gesture-echo' + (msg.type === 'place' ? ' place' : ''); thumb.dataset.key = msg.key; thumb.dataset.path = JSON.stringify(msg.path || []); thumb.dataset.distance = String(msg.distance || 0); thumb.setAttribute('role', 'option'); thumb.setAttribute('tabindex', '0'); thumb.setAttribute('aria-selected', 'false'); thumb.title = msg.type === 'place' ? `A place with ${msg.recordings || 0} recording${msg.recordings === 1 ? '' : 's'} - tap to make it your address` : 'Someone at this shape right now'; thumb.addEventListener('click', () => this.select(thumb)); thumb.addEventListener('keydown', (e) => { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); this.select(thumb); } }); // Closer strokes render stronger; 500 is comfortably past the // relay's default threshold, so everything stays visible. const strength = Math.max(0.35, Math.min(1, 1 - msg.distance / 500)); thumb.style.setProperty('--echo-strength', String(strength)); this.echoes.prepend(thumb); while (this.echoes.children.length > MAX_ECHOES) { this.echoes.lastChild.remove(); } const dpr = window.devicePixelRatio || 1; const rect = thumb.getBoundingClientRect(); thumb.width = Math.max(1, Math.round(rect.width * dpr)); thumb.height = Math.max(1, Math.round(rect.height * dpr)); const ctx = thumb.getContext('2d'); ctx.scale(dpr, dpr); this.drawPath(ctx, msg.path, rect.width, rect.height, this.theme().echo, 1.5, 0.15); // A timeout, not requestAnimationFrame: the class must land on // a later tick for the opacity transition to run, and rAF // doesn't tick at all in headless engines. setTimeout(() => thumb.classList.add('shown'), 30); } // ── Convergence ──────────────────────────────────────────────── initGlow() { if (this.gl) return this.gl; const gl = this.glow.getContext('webgl', { alpha: true, premultipliedAlpha: true }); if (!gl) return null; const compile = (type, src) => { const s = gl.createShader(type); gl.shaderSource(s, src); gl.compileShader(s); return s; }; const prog = gl.createProgram(); gl.attachShader(prog, compile(gl.VERTEX_SHADER, GLOW_VERT)); gl.attachShader(prog, compile(gl.FRAGMENT_SHADER, GLOW_FRAG)); gl.linkProgram(prog); if (!gl.getProgramParameter(prog, gl.LINK_STATUS)) return null; gl.useProgram(prog); this.gl = gl; this.glProg = prog; this.glLoc = { aFrom: gl.getAttribLocation(prog, 'aFrom'), aTo: gl.getAttribLocation(prog, 'aTo'), aIndex: gl.getAttribLocation(prog, 'aIndex'), uT: gl.getUniformLocation(prog, 'uT'), uResolution: gl.getUniformLocation(prog, 'uResolution'), uDpr: gl.getUniformLocation(prog, 'uDpr'), uColor: gl.getUniformLocation(prog, 'uColor'), uAlpha: gl.getUniformLocation(prog, 'uAlpha'), }; this.glBufFrom = gl.createBuffer(); this.glBufTo = gl.createBuffer(); this.glBufIndex = gl.createBuffer(); return gl; } // The ghost's pixel frame - same fit drawPath uses. ghostToPx(path) { const scale = (Math.min(this.cssWidth, this.cssHeight) / 2) * 0.8; const cx = this.cssWidth / 2, cy = this.cssHeight / 2; return path.map(([x, y]) => [cx + x * scale, cy + y * scale]); } startConvergence(targetPath) { this.cancelConvergence(); if (!targetPath || this.points.length < 2) return; if (window.matchMedia('(prefers-reduced-motion: reduce)').matches) return; const gl = this.initGlow(); if (!gl) return; const dpr = window.devicePixelRatio || 1; const from = resamplePx(this.points.map((p) => [p.x, p.y]), CONVERGE_POINTS); const to = resamplePx(this.ghostToPx(targetPath), CONVERGE_POINTS); const f = new Float32Array(CONVERGE_POINTS * 2); const t = new Float32Array(CONVERGE_POINTS * 2); const idx = new Float32Array(CONVERGE_POINTS); for (let i = 0; i < CONVERGE_POINTS; i++) { f[i * 2] = from[i][0] * dpr; f[i * 2 + 1] = from[i][1] * dpr; t[i * 2] = to[i][0] * dpr; t[i * 2 + 1] = to[i][1] * dpr; idx[i] = i / (CONVERGE_POINTS - 1); } const bind = (buf, data, loc, size) => { gl.bindBuffer(gl.ARRAY_BUFFER, buf); gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW); gl.enableVertexAttribArray(loc); gl.vertexAttribPointer(loc, size, gl.FLOAT, false, 0, 0); }; gl.useProgram(this.glProg); bind(this.glBufFrom, f, this.glLoc.aFrom, 2); bind(this.glBufTo, t, this.glLoc.aTo, 2); bind(this.glBufIndex, idx, this.glLoc.aIndex, 1); gl.viewport(0, 0, this.glow.width, this.glow.height); gl.uniform2f(this.glLoc.uResolution, this.glow.width, this.glow.height); gl.uniform1f(this.glLoc.uDpr, dpr); const light = this._themeQuery.matches; const color = light ? [0x47 / 255, 0x80 / 255, 0x7e / 255] : [0x8e / 255, 0xc2 / 255, 0xc0 / 255]; gl.uniform3f(this.glLoc.uColor, color[0], color[1], color[2]); // Additive light on the dark ground; normal ink on the light one. gl.enable(gl.BLEND); if (light) gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA); else gl.blendFunc(gl.ONE, gl.ONE); this.converging = true; this.render(); const started = performance.now(); const step = (now) => { const raw = (now - started) / CONVERGE_MS; if (raw >= 1) { // Deposit the ghost, then let the glow breathe out. if (this.converging) { this.converging = false; this.render(); } const fade = (now - started - CONVERGE_MS) / CONVERGE_FADE_MS; if (fade >= 1) { this.cancelConvergence(); return; } gl.clearColor(0, 0, 0, 0); gl.clear(gl.COLOR_BUFFER_BIT); gl.uniform1f(this.glLoc.uT, 1); gl.uniform1f(this.glLoc.uAlpha, 0.32 * (1 - fade)); gl.drawArrays(gl.POINTS, 0, CONVERGE_POINTS); } else { gl.clearColor(0, 0, 0, 0); gl.clear(gl.COLOR_BUFFER_BIT); // Trailing passes give the wave a comet tail. for (const [lag, alpha] of [[0, 0.32], [0.035, 0.16], [0.07, 0.08], [0.105, 0.04]]) { gl.uniform1f(this.glLoc.uT, Math.max(0, raw - lag)); gl.uniform1f(this.glLoc.uAlpha, alpha); gl.drawArrays(gl.POINTS, 0, CONVERGE_POINTS); } } this.animFrame = requestAnimationFrame(step); }; this.animFrame = requestAnimationFrame(step); } cancelConvergence() { if (this.animFrame) cancelAnimationFrame(this.animFrame); this.animFrame = null; if (this.converging) { this.converging = false; this.render(); } if (this.gl) { this.gl.clearColor(0, 0, 0, 0); this.gl.clear(this.gl.COLOR_BUFFER_BIT); } } // ── Rendering ────────────────────────────────────────────────── // Draw a normalized (-1..1) path fitted into w×h with padding. drawPath(ctx, path, w, h, color, width, pad) { if (!path || path.length < 2) return; const scale = (Math.min(w, h) / 2) * (1 - pad); const cx = w / 2, cy = h / 2; ctx.strokeStyle = color; ctx.lineWidth = width; ctx.lineCap = 'round'; ctx.lineJoin = 'round'; ctx.beginPath(); path.forEach(([x, y], i) => { const px = cx + x * scale, py = cy + y * scale; if (i === 0) ctx.moveTo(px, py); else ctx.lineTo(px, py); }); ctx.stroke(); } render() { if (!this.ctx) return; const t = this.theme(); this.ctx.clearRect(0, 0, this.cssWidth, this.cssHeight); if (this.ghost && !this.converging) { this.drawPath(this.ctx, this.ghost, this.cssWidth, this.cssHeight, t.ghost, 2, 0.2); } if (this.points.length >= 1) { this.ctx.strokeStyle = t.stroke; this.ctx.lineWidth = 2; this.ctx.lineCap = 'round'; this.ctx.lineJoin = 'round'; this.ctx.beginPath(); this.points.forEach((p, i) => { if (i === 0) this.ctx.moveTo(p.x, p.y); else this.ctx.lineTo(p.x, p.y); }); this.ctx.stroke(); } } stop() { this.stopped = true; if (this.animFrame) cancelAnimationFrame(this.animFrame); clearTimeout(this.emptyTimer); if (this.reconnectTimer) clearTimeout(this.reconnectTimer); if (this.ws) { // The close event still fires, but scheduleReconnect // no-ops once stopped is set. try { this.ws.close(); } catch { /* already dead */ } this.ws = null; } window.removeEventListener('resize', this._onResize); this._themeQuery.removeEventListener('change', this._onTheme); this.canvas.removeEventListener('pointerdown', this._onDown); this.canvas.removeEventListener('pointermove', this._onMove); this.canvas.removeEventListener('pointerup', this._onUp); this.canvas.removeEventListener('pointercancel', this._onUp); } } export function mountGesture(container, hidden, relayUrl) { // Dev convenience: `?relay=ws://127.0.0.1:9040` points every widget // on the page at a local relay (prod relays reject foreign Origins). const override = new URLSearchParams(window.location.search).get('relay'); return new GestureWidget(container, hidden, override || relayUrl); }