v1.1.3: Radix-composable buttons, meter ballistics/dBFS/loudness, PanKnob

- PushButton/Button forward native button props (...rest) and compose their own event handlers with consumer/Radix-injected ones, so a Button works as a Radix `asChild` trigger (dropdowns/tooltips/popovers). Prop types now extend React.ButtonHTMLAttributes. - Meter gains opt-in metering: `ballistics` (PPM attack/decay), `peakDecay` (peak-hold fall tail), `scale="db"` (feed amplitude → dBFS with reference lines; min/max default -60/0), and `integrated` (windowed LUFS-ish loudness readout + marker). New rAF engine in meterEngine.ts with ampToDb/dbToAmp helpers; default behavior unchanged. - New `PanKnob` — bipolar stereo pan: fills from center, center detent, L<n>/C/R<n> readout, -50..50 default. - Docs: ApiDocs rows + recipes (dBFS meter, pan strip, Button-as-trigger), gallery cards (dBFS meter, Pan) + a Regenerate Button in the panel. CHANGELOG 1.1.3; version 1.1.3; install URLs bumped. Library + docs typecheck and build; 46 tests pass. - Meter dBFS readout: muted-grey unit labels (LUFS matched to dB), value-first layout in an aligned 2-column grid so peak/loudness decimals line up, and ghost pad digits removed — the loudness row no longer looks like a stray tag. - Action buttons (Button / PushButton mode="action") no longer show an LED by default — an action has no state to indicate. led defaults to 'strip' for toggle/momentary and false for action; led="dot"/"strip" opts back in. - Meter dBFS readout: units (dB / LUFS) sit centered directly under each value; grid alignment tidied and ghost pad digits removed. Docs: dBFS-meter card moved next to the Meters card (same component) + a horizontal example.
2026-07-14 11:16:44 -07:00 · 2026-07-14 11:16:44 -07:00 · d183d7d16b
commit d183d7d16b
parent 605c38af51
15 changed files with 644 additions and 80 deletions
--- a/README.md
+++ b/README.md
@ -35,10 +35,11 @@ import { MetalKnob, LEDKnob, Fader, logTaper } from 'dreamknob'
  rounding, discrete `values` lists, evenly spaced detents (`steps`), linear / log /
  power / custom tapers.
 - **Styles**: `FlatKnob`, `MetalKnob`, `RubberKnob`, `VintageKnob`, `LEDKnob`, `NeonKnob`,
-  `SteppedKnob`, `ImageKnob` (film-strips), `Fader`, `LEDFader`, `Meter`, `MeterBridge`,
-  `Gauge`, `XYPad`, `PushButton`, `IndicatorLamp`, `LampRow`, `ToggleSwitch`,
-  `SegmentSwitch`, `TransportButton`, `ScrubField`, `SegmentDisplay`, `AlphaDisplay`,
-  plus `LabeledField`/`Rack` layout — every color themeable per instance.
+  `SteppedKnob`, `PanKnob`, `ImageKnob` (film-strips), `Fader`, `LEDFader`, `Meter`
+  (PPM ballistics · dBFS · loudness), `MeterBridge`, `Gauge`, `XYPad`, `PushButton`,
+  `Button`, `IndicatorLamp`, `LampRow`, `ToggleSwitch`, `SegmentSwitch`,
+  `TransportButton`, `ScrubField`, `SegmentDisplay`, `AlphaDisplay`, plus
+  `LabeledField`/`Rack` layout — every color themeable per instance.
 - **Composable**: `<Knob>` + primitives (`Arc`, `Pointer`, `Ticks`, `TickLabels`, `Face`,
  `KnobValue`, `KnobLabel`, `GlowFilter`) for custom designs, or go fully headless with
  `useKnob`.
@ -50,7 +51,7 @@ See `packages/dreamknob/README.md` and the docs app for the full API.
 The easiest way is the published release on our Forgejo:

 ```bash
-pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.2/dreamknob-1.1.2.tgz
+pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.3/dreamknob-1.1.3.tgz
 ```

 Or build locally — the package builds to `packages/dreamknob/dist` (ESM + CJS + types):
--- a/apps/docs/src/sections/ApiDocs.tsx
+++ b/apps/docs/src/sections/ApiDocs.tsx
@ -128,14 +128,15 @@ export const ApiDocs: React.FC = () => (
        <Row name="<LEDKnob />" type="digital" desc="Segmented LED ring + seven-segment readout. color, offColor, segments, digits, displayDecimals (any precision), unit label under the digits." />
        <Row name="<NeonKnob />" type="2D" desc="Glowing arc + dot pointer. color, trackColor, arcFrom." />
        <Row name="<SteppedKnob />" type="selector" desc="Detented switch. positions (named) or steps (numeric), color, faceColor." />
+        <Row name="<PanKnob />" type="2D · bipolar" desc="Stereo pan: fills from center, snaps to a center detent, reads out L<n>/C/R<n>. Defaults to −50…50 centered at 0; pass min/max for other conventions." />
        <Row name="<Fader />" type="linear" desc="Channel fader. orientation, length, breadth, color, tickCount, showFill, unit, format, valuePosition ('top' | 'end' | 'none'), fill (stretch to container)." />
        <Row name="<LEDFader />" type="linear · digital" desc="Segmented LED meter-fader. orientation, length, segments, color or zones ([{upTo, color}] — defaults to the theme's green/amber/red), glow, digits, unit, fill (stretch to container)." />
        <Row name="<ImageKnob />" type="sprite" desc="Film-strip knob (KnobMan-style PNG strips): src, frames, stripOrientation. Photoreal skins with zero drawing code." />
-        <Row name="<Meter />" type="display" desc="Read-only LED level meter: value (number or [l, r, ...]), zones (theme green/amber/red), peakHold, peakColor, orientation, unit, fill (stretch to container), disabled, seven-segment readout. Clip LED: showClip, clipThreshold, clipHold (ms or 'latch'), clipColor, onClip." />
+        <Row name="<Meter />" type="display" desc="LED level meter: value (number or [l, r, ...]), zones, peakHold, peakDecay (fall tail), ballistics (PPM attack/decay), scale='db' (feed amplitude → dBFS + reference lines), integrated (windowed loudness), fill, disabled, seven-seg readout, clip LED (showClip/clipThreshold/clipHold 'latch'/clipColor/onClip). All the new metering is opt-in." />
        <Row name="<MeterBridge />" type="display" desc="Labeled multi-strip meter block: channels ([{label, value, clipValue?}]), per-channel peak-hold text, shared clip LED — the mixer meter row, prebuilt." />
        <Row name="<XYPad />" type="2D control" desc="Two-parameter pad: x/y axis configs (each with min/max/step/invert/detents), drag + arrow keys (arrows follow the visual direction), grid, crosshair, Escape cancel, double-click reset." />
-        <Row name="<Button />" type="action" desc="Click-to-fire command button in the panel style (Regenerate, Add, Apply). PushButton locked to mode='action' — never latches, press-down + LED flash, onClick. led: 'dot' (default) | 'strip' | false." />
-        <Row name="<PushButton />" type="switch" desc="Panel button: mode 'toggle' | 'momentary' | 'action', controlled/uncontrolled, aria-pressed. led: 'strip' | 'dot'. leadingIcon slot tinted to the LED." />
+        <Row name="<Button />" type="action" desc="Click-to-fire command button in the panel style (Regenerate, Add, Apply). PushButton locked to mode='action' — never latches, press-down, onClick. No LED by default (an action has no state); opt in with led='dot' | 'strip'. Forwards native button props → usable as a Radix asChild trigger." />
+        <Row name="<PushButton />" type="switch" desc="Panel button: mode 'toggle' | 'momentary' | 'action', controlled/uncontrolled, aria-pressed. led defaults to 'strip' for toggle/momentary (state) and off for action; also 'dot'. leadingIcon slot. Forwards ...rest and composes handlers, so it works as a dropdown/tooltip/popover trigger." />
        <Row name="<IndicatorLamp />" type="switch · display" desc="Panel LED lamp: pressable toggle (role='switch') or read-only status light, blink, momentary, label either side (labelSize to shrink the caption below its 10px floor) — the checkbox, in hardware form." />
        <Row name="<SegmentSwitch />" type="selector" desc="Segmented option switch (radiogroup): options list, LED tick on the active cell, arrow/Home/End keys, controlled/uncontrolled index." />
        <Row name="<ScrubField />" type="numeric field" desc="After-Effects-style number field: drag the label to scrub (Shift = fine), click to type (Enter commits, Esc reverts), arrows step, wheel nudges. role='spinbutton'." />
@ -311,12 +312,25 @@ function MyKnob() {
  <ToggleSwitch defaultOn showStateLabel />
 </LabeledField>

-// A declarative channel strip
+// A declarative channel strip — now with a pan knob
 <Rack orientation="column" title="Channel 1">
  <FlatKnob label="Gain" sublabel="dB" />
+  <PanKnob size={56} defaultValue={0} />
  <Fader orientation="horizontal" fill valuePosition="end" />
  <Meter value={level} min={-60} max={6} fill orientation="horizontal" />
-</Rack>`}
+</Rack>
+
+// A pro dBFS meter — feed amplitude, get ballistics + peak-decay + loudness
+<Meter value={[ampL, ampR]} scale="db" ballistics
+  peakHold={1500} peakDecay={0.25} integrated showValue unit="dB" />
+
+// A Button as a Radix dropdown trigger (it forwards + composes handlers)
+<DropdownMenu>
+  <DropdownMenuTrigger asChild>
+    <Button led={false}>Add channel</Button>
+  </DropdownMenuTrigger>
+  <DropdownMenuContent>{/* … */}</DropdownMenuContent>
+</DropdownMenu>`}
      />

      <h3 className="api-h">Precision &amp; number handling</h3>
--- a/apps/docs/src/sections/Buttons.tsx
+++ b/apps/docs/src/sections/Buttons.tsx
@ -82,7 +82,7 @@ export const Buttons: React.FC = () => {
            </Button>
            <Button
              color="#ff4d6b"
-              led={false}
+              led="strip"
              leadingIcon={<Glyph>✕</Glyph>}
              onClick={() => setFired(n => n + 1)}
              aria-label="Clear"
@ -131,9 +131,10 @@ export const Buttons: React.FC = () => {

        <p className="section-sub" style={{ marginTop: 20 }}>
          <code>&lt;Button&gt;</code> is <code>&lt;PushButton mode=&quot;action&quot;&gt;</code> —
-          it never latches, shows a press-down and a brief LED flash, and calls{' '}
-          <code>onClick</code>. <code>led=&quot;dot&quot;</code> gives the corner-dot
-          look; <code>led=&#123;false&#125;</code> a plain button.
+          it never latches, shows a press-down, and calls <code>onClick</code>. It has{' '}
+          <strong>no LED by default</strong> — an action has no state to indicate, unlike a
+          toggle. Add <code>led=&quot;dot&quot;</code> for a corner dot that flashes on
+          press, or <code>led=&quot;strip&quot;</code> for the full strip.
        </p>
      </div>
    </section>
--- a/apps/docs/src/sections/Gallery.tsx
+++ b/apps/docs/src/sections/Gallery.tsx
@ -2,6 +2,7 @@ import React from 'react';
 import {
  AlphaDisplay,
  Arc,
+  Button,
  DreamknobProvider,
  Fader,
  FlatKnob,
@ -18,6 +19,7 @@ import {
  Meter,
  MeterBridge,
  NeonKnob,
+  PanKnob,
  Pointer,
  PushButton,
  Rack,
@ -280,7 +282,10 @@ const PanelDemo: React.FC = () => {
      <LabeledField label="Fresh seed" labelWidth={78}>
        <ToggleSwitch on={fresh} onChange={setFresh} color="#c9a6ff" showStateLabel aria-label="Fresh seed" />
      </LabeledField>
+      <div style={{ display: 'flex', gap: 8, alignItems: 'center' }}>
        <SegmentSwitch options={['SOLID', 'GRAD', 'NOISE']} value={mode} onChange={setMode} color="#c9a6ff" aria-label="Fill mode" />
+        <Button color="#c9a6ff" size={30} title="Regenerate the world" aria-label="Regenerate">↻</Button>
+      </div>
      <LampRow
        lamps={[
          { label: 'Cue', on: playing, color: '#3df2ad' },
@ -292,6 +297,61 @@ const PanelDemo: React.FC = () => {
  );
 };

+const DbMeterDemo: React.FC = () => {
+  // Drive with linear amplitude; the meter converts to dBFS internally.
+  const [amp, setAmp] = React.useState<[number, number]>([0.3, 0.28]);
+  React.useEffect(() => {
+    let t = 0;
+    const id = setInterval(() => {
+      t += 0.11;
+      const spike = Math.random() < 0.05 ? 0.4 : 0;
+      setAmp([
+        Math.max(0.001, Math.min(1.2, 0.34 + Math.sin(t) * 0.22 + Math.random() * 0.16 + spike)),
+        Math.max(0.001, Math.min(1.2, 0.32 + Math.sin(t * 1.25 + 1) * 0.22 + Math.random() * 0.16 + spike)),
+      ]);
+    }, 90);
+    return () => clearInterval(id);
+  }, []);
+  return (
+    <div style={{ display: 'flex', flexDirection: 'column', gap: 20, alignItems: 'center' }}>
+      <Meter
+        value={amp}
+        scale="db"
+        ballistics
+        peakHold={1400}
+        peakDecay={0.22}
+        integrated
+        clipThreshold={0}
+        length={140}
+        showValue
+        unit="dB"
+        label="Vertical"
+        aria-label="dBFS meter"
+      />
+      <Meter
+        value={amp}
+        scale="db"
+        ballistics
+        peakHold={1400}
+        peakDecay={0.22}
+        clipThreshold={0}
+        orientation="horizontal"
+        length={190}
+        breadth={14}
+        label="Horizontal"
+        aria-label="dBFS meter horizontal"
+      />
+    </div>
+  );
+};
+
+const PanDemo: React.FC = () => (
+  <div style={{ display: 'flex', gap: 22, alignItems: 'center' }}>
+    <PanKnob size={84} defaultValue={0} color="#4cc2ff" aria-label="Pan center" />
+    <PanKnob size={84} defaultValue={-30} color="#3df2ad" label="Track 2" aria-label="Pan left" />
+  </div>
+);
+
 const ImageKnobDemo: React.FC = () => {
  const src = useGeneratedStrip();
  if (!src) return null;
@ -509,6 +569,10 @@ export const Gallery: React.FC = () => (
          <MeterDemo />
        </Card>

+        <Card title="dBFS meter" desc="The same <Meter>, in dB mode: feed linear amplitude and it shows dBFS with PPM ballistics, a peak-decay tail, reference lines and a windowed loudness readout." tag="<Meter scale='db' ballistics integrated />">
+          <DbMeterDemo />
+        </Card>
+
        <Card title="Lamps & switches" desc="A segmented option switch, pressable indicator lamps (blink included) and a corner-dot button — the whole panel family." tag="<SegmentSwitch /> · <IndicatorLamp />">
          <LampSwitchDemo />
        </Card>
@ -536,6 +600,10 @@ export const Gallery: React.FC = () => (
          <PanelDemo />
        </Card>

+        <Card title="Pan" desc="Bipolar stereo pan: fills from center, snaps to a center detent, and reads out L/C/R." tag="<PanKnob />">
+          <PanDemo />
+        </Card>
+
        <Card title="Gradient arc" desc="Position-anchored gradient — the red zone stays at the top of travel." tag="<Arc gradient={...} />">
          <Knob size={96} min={-60} max={6} step={0.5} defaultValue={-8} aria-label="Gradient arc demo">
            <Arc
--- a/apps/docs/src/sections/GettingStarted.tsx
+++ b/apps/docs/src/sections/GettingStarted.tsx
@ -30,12 +30,12 @@ export const GettingStarted: React.FC = () => (

      <Step n={1} title="Install">
        <CodeBlock
-          code={`pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.2/dreamknob-1.1.2.tgz\n# (or npm install <same url>)  ·  peer deps: react >= 18, react-dom >= 18`}
+          code={`pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.3/dreamknob-1.1.3.tgz\n# (or npm install <same url>)  ·  peer deps: react >= 18, react-dom >= 18`}
        />
        <p className="api-note" style={{ marginTop: 10 }}>
          Installs straight from the{' '}
          <a href="https://git.dreamodus.software/Dreamodus/DreamKnob/releases">
-            v1.1.2 release
+            v1.1.3 release
          </a>{' '}
          on our Forgejo. Zero runtime dependencies, ESM + CJS, full TypeScript types. No
          CSS file to import — everything is SVG and inline styles.
--- a/apps/docs/src/sections/Hero.tsx
+++ b/apps/docs/src/sections/Hero.tsx
@ -25,10 +25,10 @@ export const Hero: React.FC = () => {
          range, any decimal precision, and colors you fully control.
        </p>
        <div className="install">
-          <span>pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.2/dreamknob-1.1.2.tgz</span>
+          <span>pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.3/dreamknob-1.1.3.tgz</span>
          <button
            onClick={() => {
-              navigator.clipboard.writeText('pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.2/dreamknob-1.1.2.tgz');
+              navigator.clipboard.writeText('pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.3/dreamknob-1.1.3.tgz');
              setCopied(true);
              setTimeout(() => setCopied(false), 1400);
            }}
--- a/packages/dreamknob/CHANGELOG.md
+++ b/packages/dreamknob/CHANGELOG.md
@ -1,5 +1,45 @@
 # Changelog

+## 1.1.3 — 2026-07-14
+
+Fourth integration-feedback release — a composability fix for buttons, a much
+smarter meter, and the pan control the mixer was missing.
+
+### Buttons
+- **Action buttons no longer show an LED by default.** `Button` (and
+  `PushButton mode="action"`) are plain by default — an action has no state to
+  indicate. `led` defaults to `'strip'` for `toggle`/`momentary` (which do have
+  a state) and to `false` for `action`; pass `led="dot"` / `led="strip"` to opt
+  a command button back in.
+
+### Buttons compose as Radix triggers
+- `PushButton` / `Button` now forward unknown props (`...rest`) to the
+  underlying `<button>` and **compose** their own event handlers with any the
+  consumer (or a Radix `asChild` slot) injects. A `Button` can now be a
+  dropdown / tooltip / popover trigger: `onPointerDown`, `onKeyDown`,
+  `data-state`, `aria-expanded` etc. all reach the DOM and fire alongside the
+  button's own press behavior. The prop types now extend the native button
+  attributes.
+
+### Meter — ballistics, dBFS, loudness
+- **`ballistics`** — PPM-style attack/decay smoothing of the displayed level
+  (`true` ≈ 5 ms attack / 350 ms decay, or `{ attack, decay }` in ms).
+- **`peakDecay`** — the peak-hold marker falls with a decay tail (normalized
+  units/second) after `peakHold` instead of snapping back.
+- **`scale="db"`** — feed linear amplitude (0..1) and the meter displays dBFS;
+  `min`/`max` default to -60 / 0 dB and faint reference gridlines are drawn
+  (`showScale` / `referenceTicks` to tune). New `ampToDb` / `dbToAmp` helpers.
+- **`integrated`** — a time-windowed loudness estimate (LUFS-ish on the dB
+  scale — a windowed mean of channel power, not a full BS.1770 measurement),
+  shown as a secondary readout and a marker line (`integrationWindow`,
+  `loudnessColor`).
+- All of the above are opt-in; the default meter behaves exactly as before.
+
+### New component
+- **`PanKnob`** — a bipolar stereo-pan knob: fills from center, snaps to a
+  center detent, reads out `L<n>` / `C` / `R<n>`. Defaults to a −50…50 range
+  centered at 0.
+
 ## 1.1.2 — 2026-07-14

 Third integration-feedback release — a general action button, responsive
--- a/packages/dreamknob/README.md
+++ b/packages/dreamknob/README.md
@ -5,7 +5,7 @@ headless core, any number range, any decimal precision, and colors you fully con
 Zero runtime dependencies.

 ```
-pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.2/dreamknob-1.1.2.tgz
+pnpm add https://git.dreamodus.software/Dreamodus/DreamKnob/releases/download/v1.1.3/dreamknob-1.1.3.tgz
 ```

 (Latest release tarballs: https://git.dreamodus.software/Dreamodus/DreamKnob/releases)
@ -95,14 +95,16 @@ import {
  LEDKnob,      // segmented LED ring + true seven-segment readout
  NeonKnob,     // glowing arc for dark UIs
  SteppedKnob,  // detented selector (positions={['LP','BP','HP']})
+  PanKnob,      // bipolar stereo pan — center detent, L<n>/C/R<n> readout
  Fader,        // linear channel fader, vertical or horizontal
  LEDFader,     // segmented LED meter-fader with color zones
  ImageKnob,    // film-strip sprite knob (KnobMan-style PNG strips)
-  Meter,        // read-only LED level meter — mono or multi-channel (value={[l, r]})
+  Meter,        // LED level meter — multi-channel, PPM ballistics, dBFS scale, loudness
  MeterBridge,  // labeled multi-strip meter block with per-channel peak text
  Gauge,        // read-only radial arc meter (round sibling of Meter) for CPU/RAM/load
  XYPad,        // two-parameter pad (cutoff/resonance, vector mixing)
-  PushButton,   // panel button with LED strip or corner dot (toggle or momentary)
+  PushButton,   // latch/hold panel button — LED strip or corner dot (toggle/momentary)
+  Button,         // click-to-fire command button (no LED by default; led="dot" opt-in)
  IndicatorLamp,  // pressable LED lamp — the hardware checkbox (blink, momentary)
  LampRow,        // row of indicator lamps with console-print captions
  ToggleSwitch,   // rocker/slider boolean — the knob slides OFF↔ON
@ -118,7 +120,10 @@ import {

 Knob skins also take `sublabel` (a second caption line) and `labelSize` (caption
 size independent of the dial); `Meter` and `Fader` take `fill` to stretch to their
-container.
+container. `Meter` adds `ballistics` (PPM attack/decay), `peakDecay`, `scale="db"`
+(feed amplitude, show dBFS) and `integrated` (windowed loudness) — all opt-in.
+`PushButton`/`Button` forward native button props and compose handlers, so a
+`Button` works as a Radix `asChild` trigger.

 ## Theming

--- a/packages/dreamknob/package.json
+++ b/packages/dreamknob/package.json
@ -1,6 +1,6 @@
 {
  "name": "dreamknob",
-  "version": "1.1.2",
+  "version": "1.1.3",
  "description": "A feature-full, studio-grade React knob & fader library. Rotary, linear, 2D, 3D, digital and analog styles with a headless core.",
  "license": "MIT",
  "author": "Dreamodus Software Inc.",
--- a/packages/dreamknob/src/index.ts
+++ b/packages/dreamknob/src/index.ts
@ -64,10 +64,12 @@ export { VintageKnob, type VintageKnobProps } from './skins/VintageKnob';
 export { LEDKnob, type LEDKnobProps } from './skins/LEDKnob';
 export { NeonKnob, type NeonKnobProps } from './skins/NeonKnob';
 export { SteppedKnob, type SteppedKnobProps } from './skins/SteppedKnob';
+export { PanKnob, type PanKnobProps } from './skins/PanKnob';
 export { Fader, type FaderProps } from './skins/Fader';
 export { LEDFader, type LEDFaderProps, type LEDFaderZone } from './skins/LEDFader';
 export { ImageKnob, type ImageKnobProps } from './skins/ImageKnob';
 export { Meter, type MeterProps } from './skins/Meter';
+export { ampToDb, dbToAmp, type Ballistics } from './skins/meterEngine';
 export { MeterBridge, type MeterBridgeProps, type MeterBridgeChannel } from './skins/MeterBridge';
 export { Gauge, type GaugeProps } from './skins/Gauge';
 export { PushButton, type PushButtonProps, Button, type ButtonProps } from './skins/PushButton';
--- a/packages/dreamknob/src/skins/Meter.tsx
+++ b/packages/dreamknob/src/skins/Meter.tsx
@ -4,16 +4,25 @@ import type { Taper } from '../core/math';
 import { useKnobTheme } from '../core/theme';
 import type { LEDFaderZone } from './LEDFader';
 import { SegmentDisplay } from '../digital/SegmentDisplay';
+import { ampToDb, useMeterEngine, type Ballistics } from './meterEngine';

 export interface MeterProps {
  /**
   * Level to display — a single number, or an array for a multi-channel
-   * meter (e.g. `[l, r]` for stereo). The meter is read-only.
+   * meter (e.g. `[l, r]` for stereo). The meter is read-only. With
+   * `scale="db"` these are linear amplitudes (0..1); otherwise they are in the
+   * `min`..`max` domain directly.
   */
  value: number | readonly number[];
  min?: number;
  max?: number;
  taper?: Taper;
+  /**
+   * 'linear' (default) shows `value` in the `min`..`max` domain. 'db' treats
+   * `value`/`clipValue` as linear amplitude and displays dBFS; `min`/`max`
+   * then default to -60 / 0 dB.
+   */
+  scale?: 'linear' | 'db';
  orientation?: 'vertical' | 'horizontal';
  /** Travel length in px. Default: 160. */
  length?: number;
@ -35,16 +44,42 @@ export interface MeterProps {
  zones?: readonly LEDFaderZone[];
  /** Opacity of unlit segments. Default: 0.1. */
  offOpacity?: number;
+  /**
+   * Attack/decay ballistics — smooth the displayed level like a PPM meter.
+   * `true` uses ~5 ms attack / ~350 ms decay; pass `{ attack, decay }` (ms) to
+   * tune. Default: off (the level follows the value directly).
+   */
+  ballistics?: boolean | Ballistics;
  /**
   * Peak hold time in ms — the highest recent segment stays lit and falls
   * back after this long. `false` disables. Default: 1200.
   */
  peakHold?: number | false;
+  /**
+   * After `peakHold`, let the peak marker fall at this many normalized units
+   * per second (a decay tail) instead of snapping back. Requires the rAF
+   * engine (also enabled by `ballistics`/`integrated`).
+   */
+  peakDecay?: number;
  /** Peak indicator color. Defaults to the peak's zone color. */
  peakColor?: string;
+  /**
+   * Show a time-windowed loudness estimate (LUFS-ish on the 'db' scale — a
+   * mean of channel power over `integrationWindow`, not a full BS.1770
+   * measurement). Rendered as a small secondary readout + a marker line.
+   */
+  integrated?: boolean;
+  /** Loudness integration window in ms. Default: 3000. */
+  integrationWindow?: number;
+  /** Color for the integrated-loudness readout and marker line. */
+  loudnessColor?: string;
+  /** Faint reference gridlines across the meter. Default: on for scale='db'. */
+  showScale?: boolean;
+  /** Reference marks in the value domain. Defaults to dBFS marks for 'db'. */
+  referenceTicks?: readonly number[];
  /** Dedicated clip LED at the hot end (shared across channels). Default: true. */
  showClip?: boolean;
-  /** Value at/above which the clip LED lights. Default: `max`. */
+  /** Value (in the display domain — dB for scale='db') at/above which it lights. Default: `max`. */
  clipThreshold?: number;
  /**
   * Signal(s) used for clip detection when different from the displayed
@ -78,15 +113,20 @@ export interface MeterProps {
 const asArray = (v: number | readonly number[]): readonly number[] =>
  Array.isArray(v) ? v : [v as number];

+const DEFAULT_DB_TICKS = [0, -6, -12, -18, -24, -36, -48];
+
 /**
 * Read-only LED level meter with peak hold and a latching clip LED — pass an
 * array of values for stereo/multi-channel bars sharing one clip indicator.
+ * Optional PPM ballistics, a peak-decay tail, a dBFS scale and a windowed
+ * loudness readout (all opt-in).
 */
 export const Meter: React.FC<MeterProps> = ({
  value,
-  min = 0,
-  max = 100,
+  min: minProp,
+  max: maxProp,
  taper = linearTaper,
+  scale = 'linear',
  orientation = 'vertical',
  length = 160,
  fill = false,
@ -96,8 +136,15 @@ export const Meter: React.FC<MeterProps> = ({
  color,
  zones,
  offOpacity = 0.1,
+  ballistics,
  peakHold = 1200,
+  peakDecay,
  peakColor,
+  integrated = false,
+  integrationWindow = 3000,
+  loudnessColor,
+  showScale,
+  referenceTicks,
  showClip = true,
  clipThreshold,
  clipValue,
@ -117,26 +164,49 @@ export const Meter: React.FC<MeterProps> = ({
 }) => {
  const theme = useKnobTheme();
  const vertical = orientation === 'vertical';
+  const dbScale = scale === 'db';
+  const min = minProp ?? (dbScale ? -60 : 0);
+  const max = maxProp ?? (dbScale ? 0 : 100);
+
  const values = asArray(value);
  const channels = values.length;
-  const ns = values.map(v => clamp(taper.toNormalized(clamp(v, min, max), min, max), 0, 1));
+  // Value-domain per channel (dB for scale='db', else the value itself).
+  const domain = values.map(v => (dbScale ? ampToDb(v) : v));
+  const targetNs = domain.map(d => clamp(taper.toNormalized(clamp(d, min, max), min, max), 0, 1));

-  // Peaks: per channel, falling back together after `peakHold` ms of no rise.
-  const [peaks, setPeaks] = React.useState<readonly number[]>(ns);
-  React.useEffect(() => {
-    if (peakHold === false) return;
-    setPeaks(prev => {
-      const rose = ns.map((n, i) => n >= (prev[i] ?? 0));
-      if (rose.every(Boolean) || prev.length !== ns.length) return ns.map((n, i) => Math.max(n, prev[i] ?? 0));
-      return prev.map((p, i) => Math.max(p, ns[i] ?? 0));
+  // rAF engine (ballistics / peak-decay / loudness). Null on the legacy path.
+  const animated = !!ballistics || peakDecay != null || integrated;
+  const engine = useMeterEngine(targetNs, domain, {
+    enabled: animated,
+    ballistics,
+    peakHold,
+    peakDecay: peakDecay ?? null,
+    integrated,
+    integrationWindow,
+    scale,
  });
-    const t = setTimeout(() => setPeaks(ns), peakHold);
+  const levels = animated && engine ? engine.levels : targetNs;
+
+  // Legacy timer-based peaks (only when the engine is off).
+  const [legacyPeaks, setLegacyPeaks] = React.useState<readonly number[]>(targetNs);
+  React.useEffect(() => {
+    if (animated || peakHold === false) return;
+    setLegacyPeaks(prev => {
+      const rose = targetNs.map((n, i) => n >= (prev[i] ?? 0));
+      if (rose.every(Boolean) || prev.length !== targetNs.length)
+        return targetNs.map((n, i) => Math.max(n, prev[i] ?? 0));
+      return prev.map((p, i) => Math.max(p, targetNs[i] ?? 0));
+    });
+    const t = setTimeout(() => setLegacyPeaks(targetNs), peakHold);
    return () => clearTimeout(t);
    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [JSON.stringify(ns), peakHold]);
+  }, [JSON.stringify(targetNs), peakHold, animated]);
+  const peaks = animated && engine ? engine.peaks : legacyPeaks;

  // Clip: latch when any channel's raw (unclamped) signal reaches threshold.
-  const clipSignals = clipValue !== undefined ? asArray(clipValue) : values;
+  const clipSignals = (clipValue !== undefined ? asArray(clipValue) : values).map(v =>
+    dbScale ? ampToDb(v) : v,
+  );
  const hottest = Math.max(...clipSignals);
  const [clipped, setClipped] = React.useState(false);
  const clipTimer = React.useRef<ReturnType<typeof setTimeout>>();
@ -182,14 +252,20 @@ export const Meter: React.FC<MeterProps> = ({

  const clipLed = 7;
  const clipSpan = showClip ? clipLed + 3 : 0;
-  const slot = Math.max(1, (along - pad * 2 - clipSpan) / segments);
+  const innerLen = along - pad * 2 - clipSpan;
+  const slot = Math.max(1, innerLen / segments);
  const gap = Math.min(2.5, slot * 0.35);
  const segSize = Math.max(0.5, slot - gap);

+  // Position (px along the travel axis) of a normalized value, measured from
+  // the cold end.
+  const posOf = (nrm: number) =>
+    vertical ? along - pad - nrm * innerLen : pad + nrm * innerLen;
+
  const bars: React.ReactNode[] = [];
  for (let c = 0; c < channels; c++) {
    const offset = c * (breadth + chGap) + pad;
-    const lit = Math.round((ns[c] ?? 0) * segments);
+    const lit = Math.round((levels[c] ?? 0) * segments);
    const peakIdx =
      peakHold !== false && (peaks[c] ?? 0) > 0
        ? Math.min(segments - 1, Math.ceil((peaks[c] ?? 0) * segments) - 1)
@ -198,8 +274,8 @@ export const Meter: React.FC<MeterProps> = ({
      const zone = zoneFor((i + 1) / segments);
      const isPeak = i === peakIdx && i >= lit;
      const on = i < lit || isPeak;
-      const fill = isPeak ? (peakColor ?? zone) : zone;
-      const common = { rx: 1.2, fill, opacity: on ? 1 : offOpacity };
+      const barFill = isPeak ? (peakColor ?? zone) : zone;
+      const common = { rx: 1.2, fill: barFill, opacity: on ? 1 : offOpacity };
      bars.push(
        vertical ? (
          <rect
@ -224,7 +300,43 @@ export const Meter: React.FC<MeterProps> = ({
    }
  }

-  const hottestShown = Math.max(...values.map(v => clamp(v, min, max)));
+  // Reference gridlines (value domain -> position across the bar area).
+  const ticks = referenceTicks ?? (dbScale ? DEFAULT_DB_TICKS : []);
+  const drawScale = (showScale ?? dbScale) && ticks.length > 0;
+  const scaleLines: React.ReactNode[] = [];
+  if (drawScale) {
+    for (const tv of ticks) {
+      if (tv < min || tv > max) continue;
+      const nrm = clamp(taper.toNormalized(clamp(tv, min, max), min, max), 0, 1);
+      const p = posOf(nrm);
+      scaleLines.push(
+        vertical ? (
+          <line key={`s${tv}`} x1={pad} y1={p} x2={w - pad} y2={p} stroke="rgba(255,255,255,0.14)" strokeWidth={0.6} strokeDasharray="2 2" />
+        ) : (
+          <line key={`s${tv}`} x1={p} y1={pad} x2={p} y2={h - pad} stroke="rgba(255,255,255,0.14)" strokeWidth={0.6} strokeDasharray="2 2" />
+        ),
+      );
+    }
+  }
+
+  // Integrated-loudness marker line.
+  const loud = loudnessColor ?? theme.zoneWarn;
+  let loudnessLine: React.ReactNode = null;
+  if (integrated && engine && engine.integrated != null && Number.isFinite(engine.integrated)) {
+    const nrm = clamp(taper.toNormalized(clamp(engine.integrated, min, max), min, max), 0, 1);
+    if (nrm > 0.001) {
+      const p = posOf(nrm);
+      loudnessLine = vertical ? (
+        <line x1={pad} y1={p} x2={w - pad} y2={p} stroke={loud} strokeWidth={1.4} />
+      ) : (
+        <line x1={p} y1={pad} x2={p} y2={h - pad} stroke={loud} strokeWidth={1.4} />
+      );
+    }
+  }
+
+  const shownDomain = domain.length ? domain.map(d => clamp(d, min, max)) : [min];
+  const hottestShown = Math.max(...shownDomain);
+  const readoutColor = zoneFor(Math.max(...levels, 0));

  return (
    <div
@ -247,24 +359,46 @@ export const Meter: React.FC<MeterProps> = ({
        ...style,
      }}
    >
+      {(showValue || (integrated && engine && engine.integrated != null && Number.isFinite(engine.integrated))) && (
+        // Each readout is its own stack: the value with its unit centered
+        // directly underneath — peak above, loudness below.
+        <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 6 }}>
          {showValue && (
-        <div style={{ width: '100%', display: 'flex', justifyContent: 'center', alignItems: 'baseline', gap: 4 }}>
+            <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 1 }}>
              <SegmentDisplay
                value={hottestShown}
                digits={digits}
                decimals={displayDecimals}
                height={11}
-            color={zoneFor(Math.max(...ns))}
+                color={readoutColor}
                background="none"
-            ghostOpacity={0.06}
+                ghostOpacity={0}
              />
              {unit && (
-            <span style={{ fontFamily: theme.fontMono, fontSize: 10, color: theme.label, whiteSpace: 'nowrap' }}>
+                <span style={{ fontFamily: theme.fontMono, fontSize: 9, letterSpacing: '0.06em', color: theme.label, whiteSpace: 'nowrap' }}>
                  {unit}
                </span>
              )}
            </div>
          )}
+          {integrated && engine && engine.integrated != null && Number.isFinite(engine.integrated) && (
+            <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 1 }}>
+              <SegmentDisplay
+                value={clamp(engine.integrated, min, max)}
+                digits={digits}
+                decimals={displayDecimals}
+                height={9}
+                color={loud}
+                background="none"
+                ghostOpacity={0}
+              />
+              <span style={{ fontFamily: theme.fontMono, fontSize: 9, letterSpacing: '0.06em', color: theme.label, whiteSpace: 'nowrap' }}>
+                {dbScale ? 'LUFS' : 'AVG'}
+              </span>
+            </div>
+          )}
+        </div>
+      )}
      <svg
        width={fill && !vertical ? '100%' : w}
        height={fill && vertical ? '100%' : h}
@ -274,7 +408,9 @@ export const Meter: React.FC<MeterProps> = ({
        aria-hidden="true"
      >
        <rect x={0.5} y={0.5} width={w - 1} height={h - 1} rx={4} fill={faceColor} stroke="rgba(255,255,255,0.09)" />
+        {scaleLines}
        {bars}
+        {loudnessLine}
        {showClip && (
          <rect
            data-part="clip"
--- a/packages/dreamknob/src/skins/PanKnob.tsx
+++ b/packages/dreamknob/src/skins/PanKnob.tsx
@ -0,0 +1,60 @@
+import * as React from 'react';
+import { FlatKnob, type FlatKnobProps } from './FlatKnob';
+
+export interface PanKnobProps extends Omit<FlatKnobProps, 'arcFrom'> {
+  /**
+   * Readout precision for the L/R amount. Default: 0 (whole numbers).
+   * The formatter shows `C` at center, `L<n>` left, `R<n>` right.
+   */
+  panDecimals?: number;
+}
+
+/**
+ * A stereo pan control — a bipolar knob that fills from the center, snaps to a
+ * center detent, and reads out `L<n>` / `C` / `R<n>`. Defaults to a −50…50
+ * range centered at 0; pass `min`/`max` for other conventions (e.g. −1…1).
+ */
+export const PanKnob = React.forwardRef<HTMLDivElement, PanKnobProps>(function PanKnob(
+  {
+    min = -50,
+    max = 50,
+    defaultValue,
+    origin,
+    detents,
+    detentSize,
+    format,
+    label = 'Pan',
+    panDecimals = 0,
+    ...rest
+  },
+  ref,
+) {
+  const center = (min + max) / 2;
+  const panFormat = React.useMemo(
+    () =>
+      format ??
+      ((v: number) => {
+        const amount = Math.abs(v - center);
+        if (amount < Math.pow(10, -panDecimals) / 2) return 'C';
+        const n = amount.toFixed(panDecimals);
+        return v < center ? `L${n}` : `R${n}`;
+      }),
+    [format, center, panDecimals],
+  );
+
+  return (
+    <FlatKnob
+      ref={ref}
+      arcFrom="center"
+      min={min}
+      max={max}
+      defaultValue={defaultValue ?? center}
+      origin={origin ?? center}
+      detents={detents ?? [center]}
+      detentSize={detentSize ?? 0.04}
+      format={panFormat}
+      label={label}
+      {...rest}
+    />
+  );
+});
--- a/packages/dreamknob/src/skins/PushButton.tsx
+++ b/packages/dreamknob/src/skins/PushButton.tsx
@ -1,7 +1,16 @@
 import * as React from 'react';
 import { useKnobTheme } from '../core/theme';

-export interface PushButtonProps {
+/** Call every handler in order (skipping undefined) — for merging our own
+ * handlers with consumer/Radix-injected ones on the same event. */
+const chain =
+  <E,>(...fns: Array<((e: E) => void) | undefined>) =>
+  (e: E) => {
+    for (const fn of fns) if (typeof fn === 'function') fn(e);
+  };
+
+export interface PushButtonProps
+  extends Omit<React.ButtonHTMLAttributes<HTMLButtonElement>, 'onChange' | 'onClick'> {
  /** Controlled pressed state. Pair with `onChange`. */
  pressed?: boolean;
  defaultPressed?: boolean;
@ -17,9 +26,10 @@ export interface PushButtonProps {
  /** LED / active color. */
  color?: string;
  /**
-   * LED style: 'strip' (default, above the caption), 'dot' (small corner
-   * dot — scales down better for icon-only toggles), or false for none.
-   * `true` is an alias for 'strip'.
+   * LED style: 'strip' (above the caption), 'dot' (small corner dot — scales
+   * down better for icon-only toggles), or false for none. `true` is an alias
+   * for 'strip'. Defaults to 'strip' for toggle/momentary (they indicate a
+   * state) and to false for `mode="action"` (a command has no state to show).
   */
  led?: boolean | 'strip' | 'dot';
  /** Button height in px. Default: 36. */
@ -35,7 +45,6 @@ export interface PushButtonProps {
  children?: React.ReactNode;
  className?: string;
  style?: React.CSSProperties;
-  'aria-label'?: string;
 }

 /** Studio panel button with an LED strip — mute/solo/bypass in matching style. */
@ -48,7 +57,7 @@ export const PushButton = React.forwardRef<HTMLButtonElement, PushButtonProps>(
      onClick,
      mode = 'toggle',
      color,
-      led = true,
+      led: ledProp,
      size = 36,
      width,
      disabled = false,
@ -57,12 +66,15 @@ export const PushButton = React.forwardRef<HTMLButtonElement, PushButtonProps>(
      children,
      className,
      style,
-      ...aria
+      ...rest
    },
    ref,
  ) {
    const theme = useKnobTheme();
    const accent = color ?? theme.accent ?? '#4cc2ff';
+    // The LED indicates a persistent/held state, so it defaults on for
+    // toggle/momentary but off for `action` (a command has no state).
+    const led = ledProp ?? (mode === 'action' ? false : true);
    const isControlled = pressed !== undefined;
    const [internal, setInternal] = React.useState(defaultPressed);
    const [focusVisible, setFocusVisible] = React.useState(false);
@ -118,25 +130,38 @@ export const PushButton = React.forwardRef<HTMLButtonElement, PushButtonProps>(
          }
        : { onClick: () => set(!latched) };

-    return (
-      <button
-        ref={ref}
-        type="button"
-        disabled={disabled}
-        aria-pressed={mode === 'action' ? undefined : latched}
-        aria-label={aria['aria-label']}
-        data-pressed={on ? '' : undefined}
-        data-focus-visible={focusVisible ? '' : undefined}
-        className={className}
-        onFocus={e => {
+    // Merge our own handlers with any consumer/Radix-injected ones of the same
+    // name (from {...rest}), so the button works as a Radix `asChild` trigger:
+    // the injected onPointerDown/onKeyDown/data-state/aria-* all reach the DOM.
+    const restHandlers = rest as Record<string, ((e: unknown) => void) | undefined>;
+    const composedHandlers = Object.fromEntries(
+      Object.entries(momentaryProps).map(([k, fn]) => [
+        k,
+        chain(restHandlers[k], fn as (e: unknown) => void),
+      ]),
+    );
+    const handleFocus = chain(restHandlers.onFocus, (e: React.FocusEvent<HTMLButtonElement>) => {
      try {
        setFocusVisible(e.currentTarget.matches(':focus-visible'));
      } catch {
        setFocusVisible(true);
      }
-        }}
-        onBlur={() => setFocusVisible(false)}
-        {...momentaryProps}
+    });
+    const handleBlur = chain(restHandlers.onBlur, () => setFocusVisible(false));
+
+    return (
+      <button
+        {...rest}
+        ref={ref}
+        type="button"
+        disabled={disabled}
+        aria-pressed={mode === 'action' ? undefined : latched}
+        data-pressed={on ? '' : undefined}
+        data-focus-visible={focusVisible ? '' : undefined}
+        className={className}
+        onFocus={handleFocus}
+        onBlur={handleBlur}
+        {...composedHandlers}
        style={{
          position: 'relative',
          display: 'inline-flex',
@ -234,12 +259,12 @@ export interface ButtonProps
 /**
 * A normal click-to-fire command button in the studio-panel style — the
 * non-latching sibling of `PushButton`. Use it for actions (Regenerate,
- * Add, Apply, Refresh). It's `PushButton` locked to `mode="action"`; pass
- * `led="dot"` for the corner-dot look (like a Fresh Seed button) or
- * `led={false}` for a plain button.
+ * Add, Apply, Refresh). It's `PushButton` locked to `mode="action"`. Plain by
+ * default (no LED — an action has no state); pass `led="dot"` for a corner dot
+ * that flashes on press, or `led="strip"` for the full strip.
 */
 export const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
-  function Button({ led = 'dot', ...rest }, ref) {
+  function Button({ led, ...rest }, ref) {
    return <PushButton ref={ref} mode="action" led={led} {...rest} />;
  },
 );
--- a/packages/dreamknob/src/skins/meterEngine.test.ts
+++ b/packages/dreamknob/src/skins/meterEngine.test.ts
@ -0,0 +1,45 @@
+import { describe, expect, it } from 'vitest';
+import { ampToDb, dbToAmp, smoothingCoeff } from './meterEngine';
+
+describe('ampToDb', () => {
+  it('maps unity amplitude to 0 dBFS', () => {
+    expect(ampToDb(1)).toBeCloseTo(0, 6);
+  });
+
+  it('halving amplitude is about -6 dB', () => {
+    expect(ampToDb(0.5)).toBeCloseTo(-6.0206, 3);
+  });
+
+  it('a tenth is -20 dB', () => {
+    expect(ampToDb(0.1)).toBeCloseTo(-20, 6);
+  });
+
+  it('silence is -Infinity', () => {
+    expect(ampToDb(0)).toBe(-Infinity);
+    expect(ampToDb(-0.2)).toBe(-Infinity);
+  });
+
+  it('round-trips through dbToAmp', () => {
+    for (const amp of [1, 0.5, 0.25, 0.031]) {
+      expect(dbToAmp(ampToDb(amp))).toBeCloseTo(amp, 6);
+    }
+  });
+});
+
+describe('smoothingCoeff', () => {
+  it('is in (0,1) and rises with dt', () => {
+    const a = smoothingCoeff(5, 100);
+    const b = smoothingCoeff(50, 100);
+    expect(a).toBeGreaterThan(0);
+    expect(b).toBeLessThan(1);
+    expect(b).toBeGreaterThan(a);
+  });
+
+  it('reaches ~63% of the way after one time constant', () => {
+    expect(smoothingCoeff(100, 100)).toBeCloseTo(1 - Math.exp(-1), 6);
+  });
+
+  it('a shorter tau (faster attack) moves further per step', () => {
+    expect(smoothingCoeff(10, 5)).toBeGreaterThan(smoothingCoeff(10, 350));
+  });
+});
--- a/packages/dreamknob/src/skins/meterEngine.ts
+++ b/packages/dreamknob/src/skins/meterEngine.ts
@ -0,0 +1,167 @@
+import * as React from 'react';
+
+/** Linear amplitude (0..1+) to dBFS. 0 (or below) maps to -Infinity. */
+export const ampToDb = (amp: number): number => (amp <= 0 ? -Infinity : 20 * Math.log10(amp));
+
+/** dBFS back to linear amplitude. */
+export const dbToAmp = (db: number): number => Math.pow(10, db / 20);
+
+/** One-pole smoothing coefficient for a time constant `tau` (ms) over `dt` (ms). */
+export const smoothingCoeff = (dt: number, tau: number): number =>
+  1 - Math.exp(-dt / Math.max(1, tau));
+
+export interface Ballistics {
+  /** Rise time constant in ms (fast). */
+  attack?: number;
+  /** Fall time constant in ms (slow). */
+  decay?: number;
+}
+
+export interface MeterEngineOptions {
+  /** Run the rAF engine at all. When false the hook returns null (legacy path). */
+  enabled: boolean;
+  /** Smooth the displayed level with attack/decay ballistics. */
+  ballistics?: boolean | Ballistics;
+  /** Peak-hold time in ms before the peak marker starts to fall. */
+  peakHold?: number | false;
+  /** Peak fall rate in normalized units per second once the hold expires. */
+  peakDecay?: number | null;
+  /** Compute a time-windowed loudness (LUFS-ish) from `rawDomain`. */
+  integrated?: boolean;
+  /** Loudness integration window in ms. */
+  integrationWindow?: number;
+  /** 'db' integrates power in the log domain; 'linear' uses RMS. */
+  scale?: 'linear' | 'db';
+}
+
+export interface MeterEngineState {
+  /** Ballistics-smoothed (or raw) normalized levels, per channel. */
+  levels: readonly number[];
+  /** Peak-hold markers, per channel, in normalized [0,1]. */
+  peaks: readonly number[];
+  /** Windowed loudness in the value domain (dB for 'db' scale), or null. */
+  integrated: number | null;
+}
+
+const DEFAULT_ATTACK = 5;
+const DEFAULT_DECAY = 350;
+
+/**
+ * A requestAnimationFrame meter engine: attack/decay ballistics, peak-hold with
+ * a decay tail, and an optional time-windowed loudness estimate. Returns null
+ * when disabled so the caller can keep its cheap legacy (timer) path.
+ *
+ * `targetNs` are the instantaneous normalized levels; `rawDomain` are the same
+ * channels in value space (dB or linear) for loudness integration.
+ */
+export const useMeterEngine = (
+  targetNs: readonly number[],
+  rawDomain: readonly number[],
+  opts: MeterEngineOptions,
+): MeterEngineState | null => {
+  const {
+    enabled,
+    ballistics,
+    peakHold = 1200,
+    peakDecay = null,
+    integrated = false,
+    integrationWindow = 3000,
+    scale = 'linear',
+  } = opts;
+
+  const useBallistics = !!ballistics;
+  const attack = (typeof ballistics === 'object' && ballistics?.attack) || DEFAULT_ATTACK;
+  const decay = (typeof ballistics === 'object' && ballistics?.decay) || DEFAULT_DECAY;
+
+  const targetRef = React.useRef(targetNs);
+  targetRef.current = targetNs;
+  const rawRef = React.useRef(rawDomain);
+  rawRef.current = rawDomain;
+
+  const [state, setState] = React.useState<MeterEngineState>(() => ({
+    levels: targetNs,
+    peaks: targetNs,
+    integrated: null,
+  }));
+
+  // Per-channel timestamp of the last time the peak was refreshed.
+  const holdAt = React.useRef<number[]>([]);
+  // Ring buffer of {t, power} for loudness integration.
+  const powerBuf = React.useRef<{ t: number; p: number }[]>([]);
+
+  React.useEffect(() => {
+    if (!enabled) return;
+    let raf = 0;
+    let last =
+      typeof performance !== 'undefined' && performance.now ? performance.now() : 0;
+
+    const tick = (now: number) => {
+      const dt = Math.min(100, now - last);
+      last = now;
+      const tgt = targetRef.current;
+      const raw = rawRef.current;
+
+      setState(prev => {
+        const n = tgt.length;
+        const prevLevels = prev.levels.length === n ? prev.levels : tgt;
+        const prevPeaks = prev.peaks.length === n ? prev.peaks : tgt;
+
+        const levels = tgt.map((t, i) => {
+          const l = prevLevels[i] ?? 0;
+          if (!useBallistics) return t;
+          const tau = t >= l ? attack : decay;
+          return l + (t - l) * smoothingCoeff(dt, tau);
+        });
+
+        const holdMs = peakHold === false ? Infinity : peakHold;
+        const peaks = levels.map((lvl, i) => {
+          const p = prevPeaks[i] ?? 0;
+          if (lvl >= p) {
+            holdAt.current[i] = now;
+            return lvl;
+          }
+          const heldFor = now - (holdAt.current[i] ?? now);
+          if (heldFor < holdMs) return p;
+          if (peakDecay == null) return lvl; // no decay tail — track the level
+          return Math.max(lvl, p - (peakDecay / 1000) * dt);
+        });
+
+        let integratedOut = prev.integrated;
+        if (integrated) {
+          const power =
+            raw.length > 0
+              ? raw.reduce(
+                  (s, d) => s + (scale === 'db' ? Math.pow(10, d / 10) : d * d),
+                  0,
+                ) / raw.length
+              : 0;
+          const buf = powerBuf.current;
+          buf.push({ t: now, p: power });
+          while (buf.length > 1 && now - buf[0].t > integrationWindow) buf.shift();
+          const meanP = buf.reduce((s, b) => s + b.p, 0) / (buf.length || 1);
+          integratedOut =
+            scale === 'db' ? 10 * Math.log10(Math.max(meanP, 1e-12)) : Math.sqrt(meanP);
+        }
+
+        return { levels, peaks, integrated: integratedOut };
+      });
+
+      raf = requestAnimationFrame(tick);
+    };
+
+    raf = requestAnimationFrame(tick);
+    return () => cancelAnimationFrame(raf);
+  }, [
+    enabled,
+    useBallistics,
+    attack,
+    decay,
+    peakHold,
+    peakDecay,
+    integrated,
+    integrationWindow,
+    scale,
+  ]);
+
+  return enabled ? state : null;
+};