Piano synth · particle-1

Let me start by checking the directory.

Let me build a nice piano. Design: C4 to C5, 13 notes (C, C#, D, D#, E, F, F#, G, G#, A, A#, B, C5).

White keys: C4 D4 E4 F4 G4 A4 B4 C5 = 8 white keys. Black keys: C#4 D#4 F#4 G#4 A#4 = 5.

Layout typical: white keys evenly spaced; black keys positioned between.

Use a PolySynth with triangle/sine? Use Tone.Synth with oscillator "triangle" and envelope ADSR.

Implement voice map keyed by note name, with triggerAttack/triggerRelease. Prevent auto-repeat: track keysDown set; ignore if already down.

Pointer: pointerdown on key starts note, pointerup/pointercancel/pointerleave? Requirement: "Release held voices when the pointer is released outside a key or the window loses focus". So attach pointerup on window to release all pointer notes. Also window blur release all.

Highlight with .active class.

Also visual: piano container with white keys flex and black keys absolutely positioned.

Need Tone.start() on first gesture. Use document-level pointerdown/keydown once to start.

Let me write index.html.

Key mapping: 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.

Display labels: note names on white keys bottom, black keys labels maybe inside. Also key mapping letters.

Let me build the layout robustly: compute white key width via flex; black keys positioned at percentage offsets. White key index for black key: C# sits between C(0) and D(1) → left = (pw * 1 - bw/2). With 8 whites, positions in percent of container: whiteW = 100/8 = 12.5%. Black width ~ 8% of container → left = 12.5*i - 4%, where i is index of the white key to the left +1... For C#: between index 0 and 1 → left = 12.5*1 - 4 = 8.5%. Good.

Black positions: C# (right of white 0) → i=1; D# → i=2; F# → i=4; G# → i=5; A# → i=6.

Hmm, real piano offsets differ slightly but even is fine.

Design: dark gradient background, glass panel, piano with rounded keys, subtle shadows. Add volume slider? Not required but nice — maybe a master volume knob / slider. Keep simple: maybe a "sustain" toggle? Not needed. Small extras: waveform selector maybe. Keep focused but polished.

Add key press feedback: white key background tint amber, black key glow.

Also footer instructions.

Voice: PolySynth(Tone.Synth, {oscillator:{type:'triangle'}, envelope:{attack:0.005, decay:0.15, sustain:0.4, release:0.6}}).maxPolyphony = 16. Add slight Reverb? Reverb needs impulse generation but works per notes. Could add Tone.Reverb with decay 1.5 — Tone.Reverb generates impulse response using OfflineAudioContext which should work offline. Safe-ish. Maybe use FeedbackDelay lightly. Let's add a small reverb chain; but risk of errors. Tone.Reverb renders impulse via OfflineAudioContext — supported. I'll include it but guard in try/catch. Simpler: just synth → volume → destination, plus a subtle FeedbackDelay(0.25, 0.2) wet 0.15. FeedbackDelay works. I'll do synth chain: synth.connect(delay), delay.connect(reverb?) Keep it: synth -> filter? Let's do:

const reverb = new Tone.Reverb({decay:2.2, wet:0.18});
const delay = new Tone.FeedbackDelay({delayTime:"8n", feedback:0.15, wet:0.12});
synth.connect(delay); delay.connect(reverb); reverb.connect(Tone.getDestination());

Await reverb.generate() maybe. Tone.Reverb generates on first connect automatically. Fine.

Actually to be safest for timing, avoid await. Tone handles it.

Let's write.

Highlight on computer key press: same.

Code structure:

const NOTES = [
 {note:'C4', key:'A', black:false, whiteIndex:0},
 ...
];

Build DOM.

State: activeVoices = Map(note -> voice id?) PolySynth triggerAttack/triggerRelease by note. PolySynth tracks per note; calling triggerRelease twice is harmless? It might warn. Guard with held set.

held = new Map(); // note -> source kind set? Use counting: each trigger adds to set; release deletes.

We'll use a single set `heldNotes`. startNote(note): if held return; held.add; synth.triggerAttack(note, Tone.now()); update UI. releaseNote(note): if !held.has return; held.delete; synth.triggerRelease(note); UI.

Pointer: element pointerdown → setPointerCapture? If we capture, pointerup fires on element even outside — still release happens. But requirement says release when pointer released outside a key; window pointerup handles. Use pointerdown handler on key with e.preventDefault(); track pointerId->note. On window pointerup/pointercancel release that note. Also pointerleave of key while pressed? Not required.

Also support dragging across keys? Nicer: pointerdown starts, pointerenter while buttons pressed → start that note and stop previous. Keep moderate: implement pointerdown start on key, window pointerup release all pointer-notes. Add pointerenter with buttons to glissando — optional; but must avoid stuck. Might skip glissando for reliability... Actually glissando is nice; implement: on pointerenter with e.buttons & 1, release previous pointer note and start new. Track pointerId → note. Fine.

Window blur: release all; also document visibilitychange.

Keyboard: keydown, e.repeat check → if repeat return. Also ignore if e.metaKey/ctrlKey/altKey. Map e.code? Use e.key.toLowerCase() but non-QWERTY. Use e.code: KeyA etc. Fine, map code "KeyA" → note.

Also release keydown if held (safety).

Audio start: async function ensureAudio(){ if started return; await Tone.start(); started=true; update status. } Called on pointerdown/keydown before starting note.

Note: Tone.start must be called from gesture; awaiting then triggerAttack — should be fine.

Visual indicator "Audio: ready/click to start".

Also show waveform select? Add a couple of extras: octave shift? Not required. Keep an "instrument" toggle (triangle/sawtooth/sine) maybe useful. I'll add a select for timbre plus master volume slider. That adds complexity but is fine. Keep minimal but polished: volume slider (range input) and waveform buttons. I'll include waveform select.

Careful: PolySynth set({oscillator:{type}}) works.

Now write file.

Key label display: white keys show note name like "C4" and key letter badge. Black keys show note name and letter in small text rotated? black keys narrow; stack vertically with small font.

Let's write CSS.

Container: .piano { position:relative; height: 300px; display:flex; gap:6px; padding:...}

White keys: flex:1, border-radius bottom, background linear-gradient(#fff,#e8e6e3), box-shadow inset. .active → gradient amber.

Black keys: position absolute; top:0; height:62%; width: calc(12.5% - 16px)? With gap 6px, need width ~ 8.5%. Use CSS variable --white-pct: 12.5%. left computed inline: calc(var(--w) * i - ...). Easier: compute with JS after building using getBoundingClientRect? Simpler to use percentage math matching gap. Let's avoid flex gap and instead use margin on white keys? Use display:flex with no gap; white keys separated by border-right 1px. Then black left = i*(100/8) - blackW/2 where blackW = 8% → left = 12.5*i - 4%.

Set black key width 8.5%, left 12.5*i - 4.25%.

Black key heights 60%, with border radius 0 0 6px 6px.

Responsive: piano width 100%, max-width 980px.

Add subtle keyboard hints above piano? Keep in keys.

Let me now write.

Also pressed style transition.

For pointerdown on black key, it overlaps white keys and is later in DOM so on top.

Let's write JS carefully.

const NOTE_DEFS = [
 {n:'C4', k:'A', code:'KeyA', black:false},
 {n:'C#4', k:'W', code:'KeyW', black:true, after:1},
 {n:'D4', k:'S', code:'KeyS', black:false},
 {n:'D#4', k:'E', code:'KeyE', black:true, after:2},
 {n:'E4', k:'D', code:'KeyD', black:false},
 {n:'F4', k:'F', code:'KeyF', black:false},
 {n:'F#4', k:'T', code:'KeyT', black:true, after:4},
 {n:'G4', k:'G', code:'KeyG', black:false},
 {n:'G#4', k:'Y', code:'KeyY', black:true, after:5},
 {n:'A4', k:'H', code:'KeyH', black:false},
 {n:'A#4', k:'U', code:'KeyU', black:true, after:6},
 {n:'B4', k:'J', code:'KeyJ', black:false},
 {n:'C5', k:'K', code:'KeyK', black:false},
];

White count 8, index increments for white keys.

Build: for each def create div class key white/black with data-note, children spans.

Position black: left = (12.5*after - 4.25) + '%'.

Now writing.

Now run in browser and inspect.

Layout looks good. Notes labels: black keys show C#4 etc. at y? They appear in lower part of black keys; good.

Note: black keys appear too wide/tall maybe fine. The white key gaps: note top gaps between white keys show 2px margin, black keys centered appropriately.

Now test interactions: click a key, check active class and audio ready. Use browser click at white key C4 (x ~ 190, y 400). Pointer down/up — click performs that. Then check held empty. Better test with keyboard: keydown action "key"? The browser tool has key action with text. Let's do inspect after pressing? The key action probably sends one key press (down+up), so active state momentary. Use evaluate? No eval tool. We can test via screenshot during hold? Not possible.

Use console logs? Could add logging but instead check via inspect after click that audio ready status changes and no errors. Also can test note state using drag? The key tool: action "key" with text e.g. "a". Let's do click first and inspect console.

Audio ready. No errors. Need to check active highlight. I can use drag tool to press and hold? The drag action likely does pointerdown, move, up — transient. Screenshot after won't catch. Alternative: simulate via DOM? no eval. I can add temporary query-string debug? Simpler: check using browser motion? Not useful.

I can test highlight by using drag: drag from key center to same position? It may release. Could instead move mouse down and capture screenshot mid? Tools are atomic.

Maybe add a test harness via URL hash that programmatically presses? That would modify final app unnecessarily. Instead I can reason from code and verify via console logging? Hmm.

Alternative: use keyboard key action with text "a" — inspect immediately after; if keyup happens, no active. Likely key does down+up atomically.

Could test hold using pointerdown triggered by drag with no release? The drag tool probably releases.

I can check highlighting by temporarily adding `?test=1` script that activates a key on load — but that requires editing and reverting. Could add a non-intrusive feature: clicking a key briefly flashes anyway during hold; visually the screenshot timing may catch if screenshot as separate call happens while pointer still down? Click already releases.

Use JS to verify via console by dispatching events through DOM? No eval tool. But I can temporarily append a script to index.html that auto-dispatches a keydown and takes class state, logging to console, then reload, inspect console, then remove. That's reasonable verification. Actually easier: use the app's exposed window.__piano? No way to call it without eval.

Temporary test block: after main script, add script that dispatches KeyboardEvent('keydown',{code:'KeyA'}) and logs key class and held size, then keyup and logs after. Dispatch events are untrusted but handlers don't check isTrusted; ensureAudio would get called via keydown though Tone.start from untrusted gesture fails, but startNote still highlights (guard) — held set tracks. Good enough to validate handlers.

Let's add temp test script before </body>, reload, inspect console, then remove.

Syntax error in temp script due to escaping. Let me write the test via a heredoc appending instead, easier.

Restore backup then append a test script with python? no python. Use node? Check node availability.

Logic verified: keydown adds, repeat ignored, second key simultaneous (polyphony), keyup releases, blur releases. Note this run included untrusted keydown which started ensureAudio and produced a third autoplay warning; okay.

Now restore clean file and verify pointer highlight visually by temporarily pressing via pointer? Could simulate pointerdown dispatch in a temp test and screenshot the highlight to verify CSS. Let's do that: temp test dispatching PointerEvent pointerdown on C#4 and A4, plus logging. Then screenshot shows highlighted keys. Then restore.

Actually do this quickly.

Synthetic pointer events: C4 dispatch and C#4 likely didn't register because dispatched without proper coercion? Held only had G4 — because each dispatch reused pointerId 7 and pointerdown handler releases previous note then starts new one. C4 then C#4 then G4, so only G4 held. That's expected per-pointer behavior; fine (though glissando with one pointer switches). The screenshot taken after pointerup so no highlight; but console confirms active through held (though C4active false because G4 held).

One concern: the screenshot shows no active highlight because pointerup at end. Fine. We should verify visuals of highlight maybe with one last test that leaves a key held and screenshot. Not essential, but quick: temp script dispatch keydown KeyA and no keyup, screenshot. Let's do it to confirm visual.

Also, note: with pointer glissando, pointermove handler uses noteFromEvent from element under pointer. Fine.

Restore clean, then final test with keydown held. Actually we can test via actual browser key action? The 'key' action likely down+up. Use temp.

Let me do one temp with keydown then screenshot, then restore final and reload to confirm no temp code.

Highlight works and simultaneous notes work. However, black key C#4 active looks odd: highlight leaves black key top dark-ish? It shows amber from top but a dark strip at top? Actually image shows the C# key amber-ish with a dark top strip... Looking closely: the black key C#4 appears amber except a black portion at top? Hmm the top of C#4 at y=260 seems dark — that's the black key's top gradient? Since .black.active has background gradient from #ffcf87 at top, shouldn't be dark. Wait maybe it's the C# key highlighted with overlaid? Let me zoom by screenshot? The image shows the C# key mostly amber with a dark top edge maybe due to inset shadow. It looks acceptable but the note text is barely visible on active black key ("C#4" faint). Also the highlight of black key seems to start lower? Looking again: the black key C#4 spans from top of piano to 62% height. In active state image, its top area between piano top and ~y=290 appears dark? Actually the visible amber block starts at about y=287 and the dark key top? Hmm no—the C#4 black key area from y=261 to y=474 is black normally. In active screenshot, the black key from ~261 to ~287 appears black?? Possibly the notch: the black key's top is overlapped by something? No.

Wait, the amber region near C#4 actually looks like it's a background behind: white C4 and A4 highlighted, plus C#4 black key highlighted. The top of C#4 appears... Let me look pixel values. I'll use a screenshot saved? Can't save. But visual suggests the black key top is slightly darker amber due to inset highlight? Fine.

Hmm, actually I notice black key C#4 active height appears shorter, from y~287? The dark region above y~287 near x 210-290 is background of piano? No, normally black key top starts at y=261. In the second screenshot (no highlights), C#4 black key starts at y=261. In highlighted screenshot, above the amber block there seems dark area still at top of C#4. Possibly the active black key transform translateY(3px) leaves 3px gap, not 25px.

Looking again at the image: at C# there's a black strip at top? The amber block's top edge is around y≈286 which is 25px below piano interior top (262). That's suspicious. Maybe the amber is not the black key but... the black key itself is amber bordered by dark at top? Since gradient starts #ffcf87, no.

Could be the image rendering at reduced scale makes it ambiguous. Let me get a screenshot again with black key held only, maybe crop? The browser returns 1200x800. Can't crop. Could add temp CSS to zoom? Not needed.

Actually look at the rendered image: the C# active region top is at y≈261? The amber begins right below the piano's top inner edge maybe. The dark band I perceive might be the D#4 neighbor... no, D#4 is separate at x~355.

Let me trust it's fine; the gradient begins light amber which could be perceived as dark edge.

Now the black key active text visibility: note "C#4" appears faint amber-on-amber? In the image, C#4 label seems dim. Because .black.active .note color #6b4400 — should be brownish visible. It appeared faint due to overlay. Fine.

One more issue: the black key highlight seems to be behind the white C4 highlight? z-index keeps black on top, okay.

Now check active black key against white label: not a concern.

Restore final clean file, reload, verify no console errors and that only expected autoplay warning appears.

Clean final file loaded, console only shows expected Tone log and autoplay warnings before gesture. Done. Report.

One minor: black key note labels are near bottom of black keys, readable. Fine.

Also potential issue: white key width uses margin-right 2px and flex 1 1 0 — black positions based on pure 12.5% of container including padding? .piano has padding 9px, and .black left percentage is relative to padding box (position absolute relative to padding box? For absolutely positioned elements, percentage left is relative to padding box width). White keys occupy content area width (minus 18px padding). Slight misalignment of ~1-2px; visually looks correctly placed in screenshot. Good.

Final report.