{
  "$schema": "https://ui.shadcn.com/schema/registry-item.json",
  "name": "pulse",
  "type": "registry:ui",
  "title": "Pulse",
  "description": "A background your data plays, not the pointer. A still grid of dots fills the box, and every event in your feed lands on it like a drop on water: a ring runs out from its point, swelling the dots it passes in the event's color, and the spot it hit stays lit for a moment after.",
  "author": "KeyframeUI <https://keyframeui.com>",
  "categories": [
    "background",
    "data",
    "canvas"
  ],
  "docs": "Live preview, examples and props: https://keyframeui.com/components/pulse",
  "dependencies": [
    "clsx",
    "tailwind-merge"
  ],
  "registryDependencies": [
    "utils"
  ],
  "files": [
    {
      "path": "components/ui/pulse.tsx",
      "type": "registry:ui",
      "content": "\"use client\";\n\nimport * as React from \"react\";\n\nimport { cn } from \"@/lib/utils\";\n\n/**\n * Keep:\n * - One rAF loop paints one canvas: the still grid is drawn once offscreen and blitted each frame,\n *   lifted dots are batched into one path per tone and level, and the loop stops when no ring is\n *   left.\n * - Only ids new since the last `events` list land; the first list is history, and events that\n *   arrive off screen or in a hidden tab are dropped, not queued.\n * - Rings add up where they cross and never cancel; past `maxRings` the oldest is dropped.\n * - Labels are stroked with the ground's color so dots never cut through them, and a repeat from\n *   the same spot takes over the label already showing.\n * - Under reduced motion there are no rings: a still spot lights by opacity alone (the dots keep\n *   one size), and labels fade in place without the rise.\n */\nconst TIMING = {\n  /** How fast a ring leaves its point, in px/s (the `ringSpeed` prop). */\n  ringSpeed: 420,\n  /** A ring fading to nothing, in seconds (the `ringDuration` prop). */\n  ringDuration: 1.6,\n  /** The afterglow at the landing point, in seconds. */\n  glow: 2,\n  /** The still spot that replaces a ring under reduced motion, in seconds. */\n  spot: 1.2,\n  /** A label in, held, and gone by, in seconds from when it lands. */\n  label: { in: 0.12, hold: 0.8, out: 1.1 },\n  /** Events per minute it lands on its own while the feed is quiet (`ambient`); 0 turns it off. */\n  ambient: 0,\n} as const;\n\n/* ─────────────────────────────────────────────────────────\n * PULSE STORYBOARD\n *\n *  rest     a still grid of faint dots fills the box, like\n *           water with nothing landing on it\n *  land     a new event (a new id in `events`) drops onto its\n *           point. A ring leaves it at 420px/s: the dots under\n *           the 60px crest swell from 1 to 2.8px and take the\n *           event's tone, a weaker second crest follows, and\n *           both fade out over 1.6s and with distance. Strength\n *           sets how far it carries: 260px for a whisper,\n *           640px for a big one\n *  glow     the landing point stays lit for 2s after the ring\n *           has left, so you can still see where it hit\n *  label    an event with a `label` prints it 10px above its\n *           point in the event's tone, 11px mono: in over\n *           120ms with a 4px rise, held, gone by 1.1s, nudged\n *           inside the box near an edge. A repeat from the\n *           same spot takes over the label already showing; a\n *           different one nearby prints a line higher. It's\n *           how a viewer tells which ring is which log line\n *  weight   dark ink on a light ground draws heavier (rest\n *           0.24, crest to 3.2px at full opacity) than light\n *           ink on a dark one (rest 0.16, crest to 2.8px), so\n *           both schemes read the same\n *  overlap  rings add up where they cross and never cancel.\n *           Past 12 at once the oldest is dropped\n *  ambient  with `ambient` set, it lands events of its own at\n *           random points while your feed is quiet, so the\n *           surface can play alone. A real event pushes the\n *           next ambient one back\n *  sleep    off screen or in a hidden tab nothing draws, and\n *           events that arrive then are dropped, not queued\n *  reduced  no rings: the dots within 40px of the point light\n *           in the tone and fade out by opacity over 1.2s.\n *           Labels fade in and out in place, without the rise\n * ───────────────────────────────────────────────────────── */\n\nconst PULSE = {\n  band: 60, // px, width of a ring's crest\n  echo: { lag: 1.3, amp: 0.35 }, // the second crest: bands behind the first, share of its height\n  reach: [260, 640], // px a ring carries at strength 0 and 1\n  gain: [0.75, 1], // crest height at strength 0 and 1\n  // Dot weight per ground: radius at rest and on a full crest (px), rest opacity, ink crest opacity range.\n  onLight: { dot: [1, 3.2], restAlpha: 0.24, crest: [0.34, 1] }, // dark ink on a light ground\n  onDark: { dot: [1, 2.8], restAlpha: 0.16, crest: [0.2, 1] }, // light ink on a dark ground\n  accentCrest: [0.35, 1], // accent dots' opacity range, either ground\n  label: { rise: 4, gap: 10, size: 11, halo: 3, edge: 6 }, // px, px, px, px, px\n  labelSame: 40, // px, a repeat of the same label this close takes over the one showing\n  labelSlots: 3, // lines a crowded spot stacks labels into\n  glow: { radius: 26 }, // px, the afterglow at the landing point\n  reduced: { radius: 40 }, // px, the still spot that replaces a ring\n  strength: 0.6, // an event's strength when it doesn't say\n  maxRings: 12,\n  levels: 10, // size and opacity steps lifted dots are batched into\n  maxDpr: 2,\n} as const;\n\nconst REDUCED = \"(prefers-reduced-motion: reduce)\";\nconst subscribeReduced = (onChange: () => void) => {\n  const query = window.matchMedia(REDUCED);\n  query.addEventListener(\"change\", onChange);\n  return () => query.removeEventListener(\"change\", onChange);\n};\n\n/** Reduced motion from the media query, false on the server and in the hydration render. */\nfunction useReduced() {\n  return React.useSyncExternalStore(\n    subscribeReduced,\n    () => window.matchMedia(REDUCED).matches,\n    () => false,\n  );\n}\n\nconst clamp01 = (t: number) => Math.min(1, Math.max(0, t));\nconst easeOut = (t: number) => 1 - (1 - t) ** 3;\n\n/** A seeded generator, so an event without a point always lands in the same place. */\nfunction seeded(key: string) {\n  let h = 2166136261;\n  for (let i = 0; i < key.length; i++) h = Math.imul(h ^ key.charCodeAt(i), 16777619);\n  return () => {\n    h = (h + 0x6d2b79f5) | 0;\n    let t = Math.imul(h ^ (h >>> 15), 1 | h);\n    t = (t + Math.imul(t ^ (t >>> 7), 61 | t)) ^ t;\n    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;\n  };\n}\n\nexport interface PulseEvent {\n  /** Stable id. An event lands once, the first time its id shows up. */\n  id: string | number;\n  /** Where it lands across the box, 0–1. A missing one gets a point picked from the id. */\n  x?: number;\n  /** Where it lands down the box, 0–1. */\n  y?: number;\n  /** 0–1: how far the ring carries and how much the dots swell. */\n  strength?: number;\n  /** The color the dots take as the ring passes. */\n  tone?: \"accent\" | \"ink\";\n  /** A few characters printed just above the point for about a second, like the region or city it came from. */\n  label?: string;\n}\n\ntype Ring = {\n  x: number;\n  y: number;\n  t0: number;\n  strength: number;\n  accent: boolean;\n  label?: string;\n  labelT0: number; // when the label started showing; a repeat from the same spot carries it on\n  labelX: number;\n  labelY: number;\n  slot: number; // lines above the point, so two nearby labels never print over each other\n};\n\n/** Relative luminance of any CSS color, read back from a 1px canvas so every color syntax works. */\nfunction luminance(color: string) {\n  const c = document.createElement(\"canvas\").getContext(\"2d\", { willReadFrequently: true });\n  if (!c) return 0;\n  c.fillStyle = color;\n  c.fillRect(0, 0, 1, 1);\n  const [r, g, b] = c.getImageData(0, 0, 1, 1).data;\n  const lin = (v: number) => {\n    const s = v / 255;\n    return s <= 0.04045 ? s / 12.92 : ((s + 0.055) / 1.055) ** 2.4;\n  };\n  return 0.2126 * lin(r) + 0.7152 * lin(g) + 0.0722 * lin(b);\n}\n\n/** The first painted background at or above `el`, for the halo behind labels. */\nfunction groundColor(el: HTMLElement | null) {\n  for (let node = el; node; node = node.parentElement) {\n    const bg = getComputedStyle(node).backgroundColor;\n    if (bg && bg !== \"transparent\" && !/rgba?\\(.*,\\s*0\\)$/.test(bg)) return bg;\n  }\n  return null;\n}\ntype Options = {\n  spacing: number;\n  ambient: number;\n  paused: boolean;\n  ringSpeed: number;\n  ringDuration: number;\n  reduced: boolean;\n};\n\nfunction createPulse() {\n  let root: HTMLElement | null = null;\n  let canvas: HTMLCanvasElement | null = null;\n  let ctx: CanvasRenderingContext2D | null = null;\n  let probes: { ink: HTMLElement; accent: HTMLElement } | null = null;\n  let ink = \"currentColor\";\n  let accent = \"currentColor\";\n  let halo: string | null = null; // the ground behind the box, stroked around labels\n  let font = \"monospace\";\n  let weight: (typeof PULSE)[\"onLight\" | \"onDark\"] = PULSE.onDark;\n  let options: Options = {\n    spacing: 18,\n    ambient: TIMING.ambient,\n    paused: false,\n    ringSpeed: TIMING.ringSpeed,\n    ringDuration: TIMING.ringDuration,\n    reduced: false,\n  };\n  let onLand: ((event: PulseEvent) => void) | null = null;\n\n  // The grid, rebuilt when the root changes size.\n  let width = 0;\n  let height = 0;\n  let dpr = 1;\n  let cols = 0;\n  let rows = 0;\n  let ox = 0;\n  let oy = 0;\n  let liftInk = new Float32Array(0);\n  let liftAccent = new Float32Array(0);\n  let buckets: Int32Array[] = []; // dot indices per tone × level\n  let bucketCounts = new Int32Array(0);\n  let rest: HTMLCanvasElement | null = null; // the still grid, blitted every frame\n\n  const rings: Ring[] = [];\n  let raf = 0;\n  let inView = false;\n  let pageVisible = true;\n  let ambientTimer = 0;\n  let ambientCount = 0;\n  const ambientRandom = seeded(\"pulse-ambient\");\n  const cleanups: (() => void)[] = [];\n\n  const now = () => performance.now() / 1000;\n  const awake = () => inView && pageVisible;\n  const ringLife = () => (options.reduced ? TIMING.spot : Math.max(options.ringDuration, TIMING.glow));\n\n  function readColors() {\n    if (!probes) return;\n    const style = getComputedStyle(probes.ink);\n    ink = style.color;\n    font = style.fontFamily || \"monospace\";\n    accent = getComputedStyle(probes.accent).color;\n    halo = groundColor(root);\n    weight = luminance(ink) < 0.4 ? PULSE.onLight : PULSE.onDark;\n    drawRest();\n  }\n\n  function drawRest() {\n    if (!rest || !width) return;\n    const c = rest.getContext(\"2d\");\n    if (!c) return;\n    c.setTransform(1, 0, 0, 1, 0, 0);\n    c.clearRect(0, 0, rest.width, rest.height);\n    c.setTransform(dpr, 0, 0, dpr, 0, 0);\n    c.fillStyle = ink;\n    c.globalAlpha = weight.restAlpha;\n    c.beginPath();\n    const r = weight.dot[0];\n    for (let row = 0; row < rows; row++) {\n      for (let col = 0; col < cols; col++) {\n        const x = ox + col * options.spacing;\n        const y = oy + row * options.spacing;\n        c.moveTo(x + r, y);\n        c.arc(x, y, r, 0, Math.PI * 2);\n      }\n    }\n    c.fill();\n  }\n\n  function layout() {\n    if (!root || !canvas) return;\n    const w = root.clientWidth;\n    const h = root.clientHeight;\n    const nextDpr = Math.min(window.devicePixelRatio || 1, PULSE.maxDpr);\n    const s = options.spacing;\n    const nextCols = Math.max(1, Math.floor(w / s));\n    const nextRows = Math.max(1, Math.floor(h / s));\n    if (w === width && h === height && nextDpr === dpr && nextCols === cols && nextRows === rows) return;\n    width = w;\n    height = h;\n    dpr = nextDpr;\n    cols = nextCols;\n    rows = nextRows;\n    ox = (w - (cols - 1) * s) / 2;\n    oy = (h - (rows - 1) * s) / 2;\n    canvas.width = Math.round(w * dpr);\n    canvas.height = Math.round(h * dpr);\n    rest ??= document.createElement(\"canvas\");\n    rest.width = canvas.width;\n    rest.height = canvas.height;\n    const count = cols * rows;\n    liftInk = new Float32Array(count);\n    liftAccent = new Float32Array(count);\n    buckets = Array.from({ length: PULSE.levels * 2 }, () => new Int32Array(count));\n    bucketCounts = new Int32Array(PULSE.levels * 2);\n    drawRest();\n    wake();\n  }\n\n  /** Adds one ring's lift to the dots it touches this frame. */\n  function addRing(ring: Ring, t: number) {\n    const age = t - ring.t0;\n    const lift = ring.accent ? liftAccent : liftInk;\n    const gain = PULSE.gain[0] + (PULSE.gain[1] - PULSE.gain[0]) * ring.strength;\n\n    if (options.reduced) {\n      const fade = clamp01(1 - age / TIMING.spot);\n      const R = PULSE.reduced.radius;\n      eachDot(ring.x, ring.y, R, (i, d) => {\n        lift[i] = Math.min(1, lift[i] + fade * (1 - d / R) * gain * 1.4);\n      });\n      return;\n    }\n\n    const radius = options.ringSpeed * age;\n    const half = PULSE.band / 2;\n    const reach = PULSE.reach[0] + (PULSE.reach[1] - PULSE.reach[0]) * ring.strength;\n    const time = clamp01(1 - age / options.ringDuration);\n    const timeFade = time * Math.sqrt(time);\n    const glow = clamp01(1 - age / TIMING.glow);\n    const echoAt = radius - PULSE.band * PULSE.echo.lag;\n    const extent = timeFade > 0 ? Math.min(radius + PULSE.band, reach) : PULSE.glow.radius;\n\n    eachDot(ring.x, ring.y, Math.max(extent, PULSE.glow.radius), (i, d) => {\n      let v = 0;\n      if (timeFade > 0 && d < reach) {\n        const k = (d - radius) / half;\n        let crest = Math.exp(-k * k);\n        if (echoAt > 0) {\n          const k2 = (d - echoAt) / half;\n          crest += PULSE.echo.amp * Math.exp(-k2 * k2);\n        }\n        v = crest * timeFade * (1 - d / reach) * gain;\n      }\n      if (glow > 0 && d < PULSE.glow.radius) {\n        v = Math.max(v, glow * glow * (1 - d / PULSE.glow.radius) * gain);\n      }\n      if (v > 0) lift[i] = Math.min(1, lift[i] + v);\n    });\n  }\n\n  /** Calls `fn` for every dot within `r` px of (x, y), with its distance. */\n  function eachDot(x: number, y: number, r: number, fn: (i: number, d: number) => void) {\n    const s = options.spacing;\n    const c0 = Math.max(0, Math.ceil((x - r - ox) / s));\n    const c1 = Math.min(cols - 1, Math.floor((x + r - ox) / s));\n    const r0 = Math.max(0, Math.ceil((y - r - oy) / s));\n    const r1 = Math.min(rows - 1, Math.floor((y + r - oy) / s));\n    for (let row = r0; row <= r1; row++) {\n      const dy = oy + row * s - y;\n      for (let col = c0; col <= c1; col++) {\n        const dx = ox + col * s - x;\n        const d = Math.sqrt(dx * dx + dy * dy);\n        if (d <= r) fn(row * cols + col, d);\n      }\n    }\n  }\n\n  function frame() {\n    raf = 0;\n    if (!ctx || !canvas || !rest) return;\n    const t = now();\n    const life = ringLife();\n    for (let i = rings.length - 1; i >= 0; i--) if (t - rings[i].t0 > life) rings.splice(i, 1);\n\n    ctx.setTransform(1, 0, 0, 1, 0, 0);\n    ctx.globalAlpha = 1;\n    ctx.clearRect(0, 0, canvas.width, canvas.height);\n    ctx.drawImage(rest, 0, 0);\n    if (!rings.length) return;\n\n    liftInk.fill(0);\n    liftAccent.fill(0);\n    for (const ring of rings) addRing(ring, t);\n\n    // Batch every lifted dot by tone and level, then fill each batch in one path.\n    bucketCounts.fill(0);\n    const L = PULSE.levels;\n    for (let i = 0; i < liftInk.length; i++) {\n      const a = liftAccent[i];\n      const n = liftInk[i];\n      const v = Math.max(a, n);\n      if (v < 0.04) continue;\n      const level = Math.min(L - 1, Math.floor(v * L));\n      const b = (a >= n ? L : 0) + level;\n      buckets[b][bucketCounts[b]++] = i;\n    }\n    ctx.setTransform(dpr, 0, 0, dpr, 0, 0);\n    const s = options.spacing;\n    const [r0, r1] = weight.dot;\n    for (let b = 0; b < L * 2; b++) {\n      const n = bucketCounts[b];\n      if (!n) continue;\n      const isAccent = b >= L;\n      const v = ((b % L) + 0.5) / L;\n      // Reduced motion changes opacity only; the dots keep one size.\n      const r = options.reduced ? r0 + (r1 - r0) * 0.6 : r0 + (r1 - r0) * v;\n      const [a0, a1] = isAccent ? PULSE.accentCrest : weight.crest;\n      ctx.globalAlpha = a0 + (a1 - a0) * v;\n      ctx.fillStyle = isAccent ? accent : ink;\n      ctx.beginPath();\n      const list = buckets[b];\n      for (let k = 0; k < n; k++) {\n        const i = list[k];\n        const x = ox + (i % cols) * s;\n        const y = oy + Math.floor(i / cols) * s;\n        ctx.moveTo(x + r, y);\n        ctx.arc(x, y, r, 0, Math.PI * 2);\n      }\n      ctx.fill();\n    }\n    drawLabels(t);\n    raf = requestAnimationFrame(frame);\n  }\n\n  /** Each labelled event's text, just above its point, on a halo of the ground so dots never cut through it. */\n  function drawLabels(t: number) {\n    if (!ctx) return;\n    const L = { ...TIMING.label, ...PULSE.label };\n    ctx.font = `500 ${L.size}px ${font}`;\n    ctx.textAlign = \"center\";\n    ctx.textBaseline = \"alphabetic\";\n    ctx.lineJoin = \"round\";\n    ctx.lineWidth = L.halo;\n    for (const ring of rings) {\n      if (!ring.label) continue;\n      const age = t - ring.labelT0;\n      if (age >= L.out) continue;\n      const fadeIn = clamp01(age / L.in);\n      const fadeOut = age < L.hold ? 1 : 1 - (age - L.hold) / (L.out - L.hold);\n      const rise = options.reduced ? 0 : (1 - easeOut(fadeIn)) * L.rise;\n      const half = ctx.measureText(ring.label).width / 2;\n      const x = Math.min(width - L.edge - half, Math.max(L.edge + half, ring.labelX));\n      // Above the point (a line higher per slot), or below it when the top edge is too close.\n      const lift = ring.slot * (L.size + 4);\n      // Reduced motion lights a 40px spot instead of a ring, so the label clears it.\n      const gap = options.reduced ? PULSE.reduced.radius * 0.6 : L.gap;\n      const above = ring.labelY - gap - lift;\n      const y =\n        Math.min(height - L.edge, above - L.size < L.edge ? ring.labelY + gap + L.size * 0.8 + lift : above) + rise;\n      ctx.globalAlpha = Math.min(fadeIn, fadeOut) * (ring.accent ? 1 : 0.8);\n      if (halo) {\n        ctx.strokeStyle = halo;\n        ctx.strokeText(ring.label, x, y);\n      }\n      ctx.fillStyle = ring.accent ? accent : ink;\n      ctx.fillText(ring.label, x, y);\n    }\n  }\n\n  function wake() {\n    if (raf || !awake() || !ctx) return;\n    raf = requestAnimationFrame(frame);\n  }\n\n  function land(event: PulseEvent) {\n    if (options.paused || !awake() || !width) return;\n    let x = event.x;\n    let y = event.y;\n    if (x === undefined || y === undefined) {\n      const random = seeded(String(event.id));\n      x ??= 0.06 + random() * 0.88;\n      y ??= 0.08 + random() * 0.84;\n    }\n    const t = now();\n    const ring: Ring = {\n      x: clamp01(x) * width,\n      y: clamp01(y) * height,\n      t0: t,\n      strength: clamp01(event.strength ?? PULSE.strength),\n      accent: event.tone === \"accent\",\n      label: event.label,\n      labelT0: t,\n      labelX: 0,\n      labelY: 0,\n      slot: 0,\n    };\n    ring.labelX = ring.x;\n    ring.labelY = ring.y;\n    if (ring.label) placeLabel(ring, t);\n    rings.push(ring);\n    if (rings.length > PULSE.maxRings) rings.splice(0, rings.length - PULSE.maxRings);\n    onLand?.(event);\n    scheduleAmbient();\n    wake();\n  }\n\n  /**\n   * Keeps labels apart. A repeat of a label still showing nearby takes it over in place, already\n   * faded in. A different one that would overlap goes on the first free line above.\n   */\n  function placeLabel(ring: Ring, t: number) {\n    const L = { ...TIMING.label, ...PULSE.label };\n    const charW = L.size * 0.62; // a mono advance, close enough to test for overlap\n    const live = rings.filter((r) => r.label && t - r.labelT0 < L.out);\n    for (const r of live) {\n      if (r.label === ring.label && Math.hypot(r.labelX - ring.x, r.labelY - ring.y) < PULSE.labelSame) {\n        ring.labelT0 = t - Math.min(t - r.labelT0, L.in);\n        ring.labelX = r.labelX;\n        ring.labelY = r.labelY;\n        ring.slot = r.slot;\n        r.label = undefined;\n        return;\n      }\n    }\n    const wide = (r: Ring) => (r.label?.length ?? 0) * charW;\n    for (let slot = 0; slot < PULSE.labelSlots; slot++) {\n      const clash = live.some(\n        (r) =>\n          r.label &&\n          Math.abs(r.labelX - ring.x) < (wide(r) + wide(ring)) / 2 + 6 &&\n          Math.abs(r.labelY - r.slot * (L.size + 4) - (ring.y - slot * (L.size + 4))) < L.size + 2,\n      );\n      if (!clash) {\n        ring.slot = slot;\n        return;\n      }\n    }\n  }\n\n  /** The next event of its own, a random wait around 60 / `ambient` seconds from now. */\n  function scheduleAmbient() {\n    window.clearTimeout(ambientTimer);\n    ambientTimer = 0;\n    if (options.ambient <= 0 || options.paused || !awake()) return;\n    const wait = (60 / options.ambient) * (0.5 + ambientRandom()) * 1000;\n    ambientTimer = window.setTimeout(() => {\n      ambientTimer = 0;\n      const accentOne = ambientRandom() < 0.25;\n      land({\n        id: `ambient-${ambientCount++}`,\n        x: 0.06 + ambientRandom() * 0.88,\n        y: 0.08 + ambientRandom() * 0.84,\n        strength: accentOne ? 0.8 : 0.3 + ambientRandom() * 0.35,\n        tone: accentOne ? \"accent\" : \"ink\",\n      });\n    }, wait);\n  }\n\n  function setAwake() {\n    if (awake()) {\n      wake();\n      scheduleAmbient();\n    } else {\n      cancelAnimationFrame(raf);\n      raf = 0;\n      rings.length = 0;\n      window.clearTimeout(ambientTimer);\n      ambientTimer = 0;\n    }\n  }\n\n  return {\n    connect(el: { root: HTMLElement; canvas: HTMLCanvasElement; ink: HTMLElement; accent: HTMLElement }) {\n      root = el.root;\n      canvas = el.canvas;\n      ctx = canvas.getContext(\"2d\");\n      probes = { ink: el.ink, accent: el.accent };\n      width = 0;\n      layout();\n      readColors();\n      pageVisible = document.visibilityState === \"visible\";\n\n      const resize = new ResizeObserver(() => layout());\n      resize.observe(root);\n      const io = new IntersectionObserver(([entry]) => {\n        inView = entry.isIntersecting;\n        setAwake();\n      });\n      io.observe(root);\n      const visibility = () => {\n        pageVisible = document.visibilityState === \"visible\";\n        setAwake();\n      };\n      document.addEventListener(\"visibilitychange\", visibility);\n\n      const scheme = window.matchMedia(\"(prefers-color-scheme: dark)\");\n      const recolor = () => {\n        readColors();\n        wake();\n      };\n      scheme.addEventListener(\"change\", recolor);\n      const themeAttrs = new MutationObserver(recolor);\n      themeAttrs.observe(document.documentElement, { attributes: true, attributeFilter: [\"class\", \"data-theme\", \"style\"] });\n\n      cleanups.push(\n        () => resize.disconnect(),\n        () => io.disconnect(),\n        () => document.removeEventListener(\"visibilitychange\", visibility),\n        () => scheme.removeEventListener(\"change\", recolor),\n        () => themeAttrs.disconnect(),\n      );\n      return () => {\n        cancelAnimationFrame(raf);\n        raf = 0;\n        window.clearTimeout(ambientTimer);\n        ambientTimer = 0;\n        rings.length = 0;\n        inView = false;\n        cleanups.splice(0).forEach((fn) => fn());\n        root = canvas = null;\n        ctx = null;\n        probes = null;\n      };\n    },\n\n    setOptions(next: Options) {\n      const relayout = next.spacing !== options.spacing;\n      if (next.paused || next.reduced !== options.reduced) rings.length = 0;\n      options = next;\n      if (relayout) layout();\n      scheduleAmbient();\n      wake();\n    },\n\n    setOnLand(fn: ((event: PulseEvent) => void) | null) {\n      onLand = fn;\n    },\n\n    land,\n  };\n}\n\nexport interface PulseProps extends React.HTMLAttributes<HTMLDivElement> {\n  /** Your feed. Each new id lands once as a ring; ids already there on mount count as history and don't. */\n  events?: PulseEvent[];\n  /** Events per minute it lands on its own while your feed is quiet. `0` turns it off. */\n  ambient?: number;\n  /** Distance between dots, in px. */\n  spacing?: number;\n  /** Draw the still grid and ignore new events. */\n  paused?: boolean;\n  /** How fast a ring runs out from its point, in px per second. */\n  ringSpeed?: number;\n  /** Seconds a ring takes to fade to nothing. */\n  ringDuration?: number;\n  /** Classes that set the dots' color (a `text-*` color). Dots at rest draw it at low opacity. */\n  inkClassName?: string;\n  /** Classes that set the color an `accent` event's ring paints (a `text-*` color). */\n  accentClassName?: string;\n  /** Called when an event's ring starts, including the ones `ambient` lands. */\n  onLand?: (event: PulseEvent) => void;\n}\n\nexport function Pulse({\n  events,\n  ambient = TIMING.ambient,\n  spacing = 18,\n  paused = false,\n  ringSpeed = TIMING.ringSpeed,\n  ringDuration = TIMING.ringDuration,\n  inkClassName,\n  accentClassName,\n  onLand,\n  className,\n  children,\n  ...props\n}: PulseProps) {\n  const rootRef = React.useRef<HTMLDivElement>(null);\n  const canvasRef = React.useRef<HTMLCanvasElement>(null);\n  const inkRef = React.useRef<HTMLSpanElement>(null);\n  const accentRef = React.useRef<HTMLSpanElement>(null);\n  const [pulse] = React.useState(createPulse);\n  const reduced = useReduced();\n\n  React.useLayoutEffect(() => {\n    const root = rootRef.current;\n    const canvas = canvasRef.current;\n    const ink = inkRef.current;\n    const accent = accentRef.current;\n    if (!root || !canvas || !ink || !accent) return;\n    return pulse.connect({ root, canvas, ink, accent });\n  }, [pulse]);\n\n  React.useEffect(() => {\n    pulse.setOptions({\n      spacing,\n      ambient,\n      paused,\n      ringSpeed: Math.max(1, ringSpeed),\n      ringDuration: Math.max(0.05, ringDuration),\n      reduced,\n    });\n  }, [pulse, spacing, ambient, paused, ringSpeed, ringDuration, reduced]);\n\n  const onLandRef = React.useRef(onLand);\n  React.useEffect(() => {\n    onLandRef.current = onLand;\n  });\n  React.useEffect(() => {\n    pulse.setOnLand((event) => onLandRef.current?.(event));\n    return () => pulse.setOnLand(null);\n  }, [pulse]);\n\n  // Land only the ids that weren't in the last list. The first list is history.\n  const seenRef = React.useRef<Set<PulseEvent[\"id\"]> | null>(null);\n  React.useEffect(() => {\n    const list = events ?? [];\n    const before = seenRef.current;\n    seenRef.current = new Set(list.map((e) => e.id));\n    if (!before) return;\n    for (const event of list) if (!before.has(event.id)) pulse.land(event);\n  }, [pulse, events]);\n\n  return (\n    <div ref={rootRef} className={cn(\"relative isolate overflow-hidden\", className)} {...props}>\n      <canvas ref={canvasRef} aria-hidden className=\"pointer-events-none absolute inset-0 -z-10 size-full\" />\n      {/* Probes the canvas reads its colors from. Defaults apply only when no class is given, so a `dark:` default can't win over yours. */}\n      <span ref={inkRef} aria-hidden className={cn(\"hidden font-mono\", inkClassName ?? \"text-zinc-900 dark:text-zinc-100\")} />\n      <span ref={accentRef} aria-hidden className={cn(\"hidden\", accentClassName ?? \"text-[#ff5a1f] dark:text-[#ff6a3d]\")} />\n      {children}\n    </div>\n  );\n}\n"
    }
  ]
}