Piano synth · mimo-v2.6-flash

Let me start by checking the working directory and the provided tone.min.js file.

Let me write the index.html file. Design:

- 13 notes: C4 C#4 D4 D#4 E4 F4 F#4 G4 G#4 A4 A#4 B4 C5
- Keys A W S E D F T G Y H U J K
- Use Tone.PolySynth with ADSR envelope, or a voice per note. To prevent auto-repeat duplicates, track active notes with a Set/Map of held state; on keydown, if already held, ignore repeat. Use `e.repeat` check and held set.

Release: on keyup, trigger release. For PolySynth, use synth.triggerRelease(note).

For pointer: pointerdown on key starts, pointerup anywhere (window) releases all pointer-held notes. Also pointerleave while held? Requirement: "Release held voices when the pointer is released outside a key or the window loses focus". So window pointerup -> release pointer-held notes. window blur -> release all. Also visibilitychange maybe.

Highlight keys while held: add class .active.

Audio activation: click/keypress anywhere -> Tone.start(). Show overlay "Click to enable audio" that disappears after start.

Console: log activation.

Let's also show computer-key mapping on each key (the letter) and note labels.

Layout: white keys 8 (C4 D4 E4 F4 G4 A4 B4 C5), black keys 5 (C#4 D#4 F#4 G#4 A#4). Position absolutely.

Let's build carefully with CSS.

White key width: e.g. 72px, container width 8*72=576.

Black keys: width ~44px, positioned at boundaries: after C (between C and D) -> left = 72 - 22 = 50; after D -> 144-22=122; after F -> 4*72-22 = 266; after G -> 5*72-22=338; after A -> 6*72-22=410.

Actually use percentage-based or fixed px with transform centering. I'll compute via CSS with a --kw variable.

For responsiveness, maybe scale container. Keep simple with px and maybe a scale transform on small screens.

Voice: Tone.PolySynth(Tone.Synth, {oscillator:{type:"triangle"}, envelope:{attack:0.01, decay:0.15, sustain:0.6, release:0.5}}) plus a filter and reverb? Reverb uses IR generation — Tone.Reverb works offline? It generates IR via offline context rendering... In sandbox, Tone.Reverb uses Tone.Offline which should work (it's not a Worklet). The addendum says Reverb works. But to be safe, I could use Tone.FeedbackDelay or just a simple filter. Let's use a Tone.Filter lowpass and Tone.FMSynth or Synth. Keep it simple: PolySynth + Filter + Gain to destination. Maybe add a light FeedbackDelay for nice sound.

PolySynth with maxPolyphony >= 3 (default 32). Good.

Voice management: keep map of note -> boolean held. Also keep track of which source (keyboard/pointer) holds.

Implementation:

```js
const activeNotes = new Set(); // currently sounding
const heldBy = new Map(); // note -> {key:bool, pointer:bool}
```

Simpler: 
- `heldKeys = new Set()` of notes started by computer keyboard
- `pointerNotes = new Set()` notes started by pointer (usually one, but multi-touch support: use pointerId map). Use map pointerId -> note.

startNote(note, source): if source set already contains note -> return (idempotent). Actually for keyboard, if note already in heldKeys, ignore (prevents repeat). Then add, highlight, synth.triggerAttack(note).

endNote(note, source): remove from set; if neither set contains note anymore -> highlight off, synth.triggerRelease(note).

Window blur: release everything (both sets clear, all highlights off, synth.releaseAll()).

pointerup on window: release all pointer notes.

Also pointerdown on a key then pointermove to another key (glissando)? Not required. Keep pointer drag: could add pointerenter while pressing for glide, optional. Skip or implement lightly — implement glissando? Not required; risk of complexity. I'll implement simple: pointerdown on key triggers; pointerup anywhere releases that pointer's note. Maybe also support dragging: pointerenter with pressed pointer starts note and releases previous. That's nice but adds risk. I'll include a simple version since pointer capture could interfere — don't use setPointerCapture, so pointerenter fires. Actually with pointer down on element, without capture, pointerenter on other keys fires when moving. Let's include it — it's straightforward and matches "pressing a screen key starts note".

Hmm but requirement says release when pointer released outside key — meaning releasing outside a key should still release the held note (i.e., window pointerup handler). Fine.

Key elements: data-note attribute.

Also prevent default for keys like space? Our keys don't include space. But 'a'..'k' typing is fine. Prevent default maybe for nothing needed. But if focus is on button, keydown triggers click — no buttons focusable? The overlay is a div/button; after activation it's removed.

Tone.start() on first user gesture: pointerdown/keydown on document. Show overlay before that; overlay click -> start.

Let's write the file.

Visual: dark background, keys with labels at bottom: note name and computer key letter.

Also add a small status line showing "Audio: on/off" and last note played maybe.

Console after activation: console.log("Tone audio started", Tone.version).

Let's write it.

Also need `touch-action: none` on keys to avoid scrolling, and `user-select:none`.

Fallback for pointer events: modern browsers fine.

Note frequencies: use note names with octave: "C4" ... "C5". In Tone, triggerAttack("C4").

Keyboard map:
A -> C4
W -> C#4
S -> D4
E -> D#4
D -> E4
F -> F4
T -> F#4
G -> G4
Y -> G#4
H -> A4
U -> A#4
J -> B4
K -> C5

Write HTML.

Structure:

```html
<div id="app">
  <header>
    <h1>Tone Piano</h1>
    <div id="status">...</div>
  </header>
  <div id="keyboard" class="keyboard">
    white keys ...
    black keys ...
  </div>
  <p class="hint">...</p>
</div>
<div id="overlay"><div class="card">Click / press any key to enable audio</div></div>
```

Generate keys via JS to keep HTML tidy? Requirement: "Display one chromatic octave... with correctly placed black keys and visible note labels." Generating in JS is fine, but if JS fails, nothing shows. JS is required anyway for sound. I'll generate in JS — cleaner and less error-prone for positions.

Actually maybe better: build keys in JS with computed positions. White keys as flex items, black keys absolutely positioned using percentage of white key width: left = (index+1)*whiteWidthPct - blackWidthPct/2, where whiteWidthPct = 100/8 = 12.5%. Black width = 7% (of container) → hmm white width 12.5%, black ~8%. left for black after white i (0-based): (i+1)*12.5 - 4 = e.g. after C (i=0): 8.5%.

Black keys are between whites: after C(i=0) → 12.5-4 = 8.5%; after D(i=1) → 25-4=21%; after F(i=3) → 50-4=46%; after G(i=4) → 62.5-4=58.5%; after A(i=5) → 75-4=71%.

Container width: min(90vw, 880px), white key width 110px max → 880.

Keyboard height ~ 260px.

Let's write.

JS details:

```js
const NOTE_ORDER = [
 {note:"C4", key:"a", type:"white", label:"C4"},
 {note:"C#4", key:"w", type:"black"},
 ...
];
```

Rendering: append white keys first in order, then black keys with data-left.

Highlight: add class 'active' to key element.

Keydown handler:
```js
window.addEventListener("keydown", e => {
  ensureAudio();
  if (e.repeat) { e.preventDefault(); return; }
  const note = KEY_TO_NOTE[e.key.toLowerCase()];
  if (!note) return;
  e.preventDefault();
  pressKeyboard(note);
});
window.addEventListener("keyup", e => { const note = ...; if(note) releaseKeyboard(note); });
```

Note: e.repeat check plus heldKeys set check.

Pointer: each key element:
```js
el.addEventListener("pointerdown", e => { e.preventDefault(); ensureAudio(); pressPointer(e.pointerId, note); });
```
window pointerup/pointercancel: release pointer note for that pointerId.
window pointermove: if any active pointer and over a key with different note → glide? I'll implement: on pointermove with active pointer, use document.elementFromPoint to find key; if different note, release old, press new. Hmm, could cause unexpected behavior during test (dragging). It's a plus. But risk: browser drag of image? no images. I'll implement glissando — actually keep it simpler: skip glissando to reduce risk? The spec doesn't require it. I'll add it anyway but carefully; elementFromPoint returns the topmost element — labels are children with pointer-events:none, so the key div is returned. Use closest('.key').

Hmm, one risk: pointermove fires a lot; but transitions are cheap. Fine, I'll include but guard.

Actually, let's not overcomplicate. I'll include glissando since it's a nice touch and easy: only for pointers currently active.

Blur handling:
```js
window.addEventListener("blur", releaseEverything);
document.addEventListener("visibilitychange", () => if(hidden) releaseEverything());
```

Synth setup:
```js
let synth;
async function ensureAudio() {
  if (!started) {
    await Tone.start();
    ...
  }
}
```
Guard against double-init with a promise flag.

```js
let audioPromise = null;
function ensureAudio(){
  if(!audioPromise){
    audioPromise = (async () => {
      await Tone.start();
      const filter = new Tone.Filter(3000, "lowpass").toDestination();
      const delay = new Tone.FeedbackDelay("8n", 0.12).connect(filter);
      delay.wet.value = 0.12;
      synth = new Tone.PolySynth(Tone.Synth, {
        maxPolyphony: 12,
        oscillator: { type: "triangle" },
        envelope: { attack: 0.005, decay: 0.25, sustain: 0.5, release: 0.6 },
        volume: -8
      }).connect(delay);
      ...
    })();
  }
  return audioPromise;
}
```

PolySynth options: `new Tone.PolySynth(Tone.Synth, options)` — options include oscillator, envelope, and also maxPolyphony? In Tone.js, maxPolyphony is a property of PolySynth; pass in options: `new Tone.PolySynth(Tone.Synth, {maxPolyphony:12, ...})` — I believe options are merged into voice options plus PolySynth options. In Tone v14/15, PolySynth constructor: `new Tone.PolySynth(Tone.Synth, {oscillator:..., envelope:...})`, and maxPolyphony set via `synth.maxPolyphony = 12`. Setting property works: `poly.maxPolyphony = 12`. Hmm, is it writable? In Tone.js PolySynth has a `maxPolyphony` public property (number). I think there's a setter... Let me check in tone.min.js: search for "maxPolyphony".

Also `volume` option: Tone.Synth options include volume (Part of Monophonic options). Should work.

Let's grep tone.min.js for maxPolyphony.

Note: is Tone a UMD global in browser? Yes, `t.Tone=e()` sets global.

Check Tone.version exists.

Also ensure `Tone.start()` returns promise.

Another consideration: the runner inlines tone.min.js — so `<script src="tone.min.js"></script>` must be a plain local tag.

Let's check a couple of API details in the min file.

Tone 14.8.49. Good.

Now write index.html.

Tone 14.8.49. PolySynth options: in v14, `new Tone.PolySynth(Tone.Synth, { ... })` merges options; maxPolyphony is a settable property on PolySynth (there's a getter/setter? In v14 PolySynth has `maxPolyphony` property set in constructor options... Let's check min code near maxPolyphony usage.

So `maxPolyphony` is read from constructor options object (`t.maxPolyphony`). Default likely 32. I'll pass `maxPolyphony: 12` in options anyway (it's read from options, so passing it works).

Now write index.html.

So `this.maxPolyphony=t.maxPolyphony` — options object can include maxPolyphony, default likely 32. Good, pass maxPolyphony in options.

Now write index.html.

`this.maxPolyphony = t.maxPolyphony` — so options can include `maxPolyphony`. Default probably 32. Good.

Now write index.html.

Let me write the complete file.

Design details:
- Background: dark gradient.
- Header with title, status pill (Audio: Off → On), last note indicator.
- Keyboard container with white keys flex + absolute black keys.
- Each key shows note label at bottom and computer key letter badge.
- Active state: white keys highlight blue-ish, black keys highlight orange.
- Overlay: full-screen, click to start.

Key data:

```js
const KEYS = [
  { note:'C4',  k:'a', type:'w' },
  { note:'C#4', k:'w', type:'b' },
  { note:'D4',  k:'s', type:'w' },
  { note:'D#4', k:'e', type:'b' },
  { note:'E4',  k:'d', type:'w' },
  { note:'F4',  k:'f', type:'w' },
  { note:'F#4', k:'t', type:'b' },
  { note:'G4',  k:'g', type:'w' },
  { note:'G#4', k:'y', type:'b' },
  { note:'A4',  k:'h', type:'w' },
  { note:'A#4', k:'u', type:'b' },
  { note:'B4',  k:'j', type:'w' },
  { note:'C5',  k:'k', type:'w' },
];
```

Black key positions: black keys in order appear after white indexes: C# after 0, D# after 1, F# after 3, G# after 4, A# after 5.

I'll compute: iterate through KEYS with whiteIndex counting; when a black key found, it belongs after previous white index. left = (prevWhiteIndex+1)*W - BW/2 where W=12.5%, BW=7.6%. left percentages: black width 7.6 → half 3.8.

C#: (1)*12.5-3.8 = 8.7
D#: 25-3.8=21.2
F#: 50-3.8=46.2
G#: 62.5-3.8=58.7
A#: 75-3.8=71.2

Rendering order: whites appended in flow (flex), blacks appended with position absolute.

Note label: show e.g. "C4", "C♯4" for black. Use ♯ char.

Also keyboard hint row: show mapping "A C4  W C#4 ..." — the mapping is displayed on keys themselves, plus a legend line.

State handling code:

```js
const kbHeld = new Set();      // notes held via computer keyboard
const ptrHeld = new Map();     // pointerId -> note
const heldCount = n => (kbHeld.has(n)?1:0) + [...ptrHeld.values()].filter(x=>x===n).length;
```

press(note, source):
```js
function press(note, id, isPointer){
  if (isPointer){ if([...ptrHeld.values()].includes(note)) return; ptrHeld.set(id, note); }
  else { if (kbHeld.has(note)) return; kbHeld.add(note); }
  if (activeCount(note) === 1) { // just became active
     synth.triggerAttack(note, Tone.now());
  }
  setHighlight(note, true);
}
```
Actually triggerAttack once per note; PolySynth triggerAttack on same note twice would create 2 voices (retrigger). Guard with count.

But if audio not ready yet (async Tone.start pending), we should await before triggerAttack. Approach: press functions are async and await ensureAudio() before triggering; also track pending state. Simpler: since ensureAudio is fast, do:

```js
async function press(note, ...){ ...state add...; highlight on; await ensureAudio(); if (still held per count) synth.triggerAttack(note); }
```

Race conditions minimal. Alternatively block UI until audio starts via overlay — overlay only dismissed on gesture; keydown gesture also dismisses. I'll keep the async pattern with a re-check.

Simplify: maintain `sounding` Set of notes currently triggered in synth.

```js
async function press(note, sourceKey){
  ...
  await ensureAudio();
  if (isActive(note) && !sounding.has(note)) { sounding.add(note); synth.triggerAttack(note); }
}
function release(note){
  ...remove from sets...
  if (!isActive(note) && sounding.has(note)) { sounding.delete(note); synth.triggerRelease(note); }
  highlight off
}
```

releaseAll (blur/pointerup): for each pointerId clear, kbHeld clear, call release per note (which triggers synth release), or simply synth.releaseAll() + clear state. Use per-note release path so state stays consistent, then also safety synth.releaseAll().

Actually on pointerup: "Release held voices when the pointer is released outside a key" — window pointerup releases the note associated with that pointerId regardless of where released. Good.

window blur → release all: clear kbHeld and ptrHeld, release each sounding note.

Also 'keyup' when window not focused handled by blur anyway.

Highlight: `keyEls.get(note).classList.toggle('active', isActive(note))`.

Status display: show active notes count / last note.

Audio overlay: click on overlay → ensureAudio then hide. Also keydown first time → ensureAudio and hide overlay (but that keydown should also start the note! Since we call ensureAudio first then press, the press awaits audio and triggers — good, overlay hides).

Overlay should not block keys after hidden: display:none.

Also add pointerup on window: e.preventDefault? No.

Prevent text selection: user-select none on keys; pointerdown preventDefault to avoid focus stealing? preventDefault on pointerdown prevents focus and text selection — ok. But then keydown events still go to window. Fine.

Also prevent keydown default for our mapped letters (prevent scrolling? letters don't scroll). Prevent anyway to avoid e.g. quick-find in Firefox (' for search — not mapped). I'll preventDefault for mapped keys only.

Glissando with pointermove: implement.

```js
window.addEventListener('pointermove', e => {
  if (!ptrHeld.has(e.pointerId)) return;
  const el = document.elementFromPoint(e.clientX, e.clientY);
  const key = el && el.closest ? el.closest('.key') : null;
  const note = key ? key.dataset.note : null;
  const cur = ptrHeld.get(e.pointerId);
  if (note && note !== cur){ pressPointerNote(e.pointerId, note); releasePointerNote(cur... ) }
});
```
Careful: pressPointerNote for new note sets ptrHeld for id to new note; we must release old note first or after. Implement movePointer(id, newNote): release old note (remove from map, release note) then press new.

Hmm ordering: release old then press new. Fine.

But glissando means moving pointer outside keys (not on a key) keeps note held (cur stays) — releasing only happens on pointerup. That matches requirement (release on pointerup anywhere).

Actually should moving off a key release? Requirement only says release on pointerup outside key. Keep held until pointerup.

Now check tone.min.js loads as global `Tone` in browser (module UMD checks `typeof exports`). In browser no exports → sets self.Tone. Good.

Let's write the file now.

Also include a legend/mapping row: "Keyboard: A C4 · W C♯4 · ..." 

Write CSS.

Then test in browser with the browser tool: click to activate audio, press keys via browser "key" action, screenshot, inspect console.

Does the browser tool have console inspection? `inspect` shows DOM/console per description: "Run index.html, inspect DOM/console, interact". I'll use inspect.

Let's write the file.

The file is saved. Let me do a quick browser verification: load, inspect, click to enable audio, press a key, screenshot, check console. Keep it fast.

Now run in the browser: reload, inspect console, click overlay, press key, screenshot.

Load OK, mapping/labels present. Now click overlay to start audio, then press a computer key and check highlight + console.

Audio started, overlay hidden, keyboard rendered with correct labels and black key positions. Status dot is still red in screenshot but text says "Audio: on" — the `.on` class was added; screenshot may have been taken before CSS paint or the dot color... Actually screenshot shows red dot with "Audio: on". The classList.add("on") happened — maybe screenshot timing. Minor.

Now test: press keyboard key 'a' (key down/up) and check highlight + attack/release logs. Use browser key action. The browser tool `key` action sends a key press (down+up probably). Let's try pressing "a" and inspecting, but down+up happens fast so highlight may already be off. Better: use `type`? Let's use key action with text "a" and immediately inspect console for attack/release logs.

Also test holding: key action may support down/up separately? Unknown. Let's just do key press and check console logs for attack+release pairs.

Also test mouse: click on a white key (pointerdown/up) → attack/release.

Let's do key press first.

Keyboard press works: attack C4 then release C4, status dot now green. Now test mouse press on a black key (pointerdown) — click on black key F#4 at ~(598, 190). A click = down+up quickly. Check attack/release logs.

Also test held highlight: I can check via pointerdown hold — the browser tool click does down+up. Let's just verify attack/release for a black key and a white key click, plus check that no stuck notes remain (`sounding()` empty).

I'll click a black key then inspect __piano state via... inspect action shows DOM/console only. Maybe I can run JS? The `inspect` action may accept? Unknown params. I'll rely on console logs.

Let's click black key F#4.

Mouse works: attack F#4 → release F#4.

Remaining quick checks worth doing: multi-note polyphony (press two/three keys) and that no stuck notes remain. The clicks were down+up so highlight visible state wasn't captured mid-hold. I could test hold via dispatching pointerdown through JS? Not easily without an eval action.

One risk: since browser `key` action sends down+up quickly, highlight unverifiable visually — but the logs prove the pairing. I'm at ~11 minutes. Let's do one last check: press three keys at once (chord) by key events in quick succession? They release too fast. 

I think verification is sufficient. One thing to double check in code: `keydown` for unmapped keys calls ensureAudio() — that triggers Tone.start on every keydown even before gesture; harmless.

Potential issue: `press()` guard for pointer: `if (Array.from(ptrHeld.values()).indexOf(note) !== -1) return;` — this blocks a second finger on the same note (fine) but also means if two different pointers... fine.

But bug: if pointer already holds note and another pointer presses same note, press returns without setting ptrHeld for the second pointer — then on pointerup of second pointer, releasePointer finds nothing → no release; first pointer still holds → correct behavior (note stays held). Good.

Edge: glissando movePointer releases old then presses new — fine.

Another check: keydown auto-repeat guard uses `e.repeat` and kbHeld. Good.

Also: release on window blur → releaseEverything. Not directly tested but code inspected.

Also the status dot red initially then green — works.

Let's do one final quick check of stuck-note state by pressing 'a' and 's' together? I can't hold with this tool. Instead, I can verify state via console by checking `window.__piano` — but no eval tool. The `inspect` action only shows DOM/console.

Actually maybe `type` action types text; `key` with text supports combos. Not holds.

I'll finish: file is saved and verified. Write brief report.

Actually, one essential issue: in the screenshot the legend wraps to two lines — fine.

Also confirm no external resources: grep for http in index.html.

No external references (the only https mention was inside the Tone.js console warning text, filtered out and it wasn't in our file anyway). File saved.

Done. Report.