src/main.ts at ccaeb59d310f2c43e69d8a90b02abfdd8c695b1f

1// Application: design editor, parameter form, run loop, live and movie

2// views, spectrogram, playback, WAV download, and the test hooks on

3// window.steelsim.

5import { type Plate, type SimParams, countInside, defaultParams, massProperties, mountPatch, nodeWeights, strikePoint, thicknessRange } from "./params.ts";

6import { DesignError, evaluatePlate, profileStats } from "./design.ts";

7import { PRESETS } from "./presets.ts";

8import { Simulation, type SimStatus } from "./sim/simulation.ts";

9import { Renderer, type ColorMode, type ViewMode } from "./render/renderer.ts";

10import { Spectrogram } from "./audio/spectrogram.ts";

11import { Player } from "./audio/player.ts";

12import { encodeWav } from "./audio/wav.ts";

13import { levelGain, peakDbfs, type LevelMode } from "./audio/level.ts";

14import { ParamForm } from "./ui/form.ts";

15import { DesignEditor } from "./ui/editor.ts";

16import { runSelfTest, selfTestPassed, type SelfTestCase } from "./selftest.ts";

18const $ = <T extends HTMLElement>(id: string) => document.getElementById(id) as T;

20/** Slope above which the shallow-shell treatment of the profile is doubtful. */

21const SLOPE_LIMIT = 0.1;

23// ---------- State ----------

25const params: SimParams = { ...defaultParams };

26let form: ParamForm;

27let editor: DesignEditor;

28let device: GPUDevice | null = null;

29let sim: Simulation | null = null;

30let renderer: Renderer | null = null;

31let running = false;

32let paused = false;

33let live = true;

34let scrubFrame = 0;

35let movieBuf: GPUBuffer | null = null;

36let movieBufFrame = -1;

37/** The design evaluated at the current spacing, or null while the script has an error. */

38let plate: Plate | null = null;

39let plateError: string | null = null;

40/** Show the design (its stress-free shape) instead of the simulation. */

41let previewMode = true;

42let preview: { plate: Plate; w0: GPUBuffer; zero: GPUBuffer; nw: GPUBuffer; hn: GPUBuffer; wmax: number; stale: boolean } | null = null;

43const spec = new Spectrogram({ windowSize: 2048, hop: 512, fmax: 5000, dbFloor: 80, logFrequency: false });

44const player = new Player();

45let lastStatsTime = 0, lastStatsSteps = 0, stepsPerSec = 0;

46let duration = params.duration;

48// ---------- Controls ----------

50const btnStart = mkButton("Start", "primary");

51const btnPause = mkButton("Pause");

52const btnStop = mkButton("Stop");

53const btnContinue = mkButton("Continue");

54const durInput = document.createElement("input");

56function mkButton(text: string, cls = ""): HTMLButtonElement {

57 const b = document.createElement("button");

58 b.textContent = text;

59 b.className = cls;

60 return b;

61}

63function buildControls(): void {

64 const c = $("controls");

65 const durRow = document.createElement("div");

66 durRow.className = "field";

67 durRow.style.width = "100%";

68 const l = document.createElement("label");

69 l.textContent = "Recorded duration";

70 durInput.type = "number";

71 durInput.step = "0.5";

72 durInput.min = "0.1";

73 durInput.value = String(duration);

74 durInput.addEventListener("change", () => {

75 const v = parseFloat(durInput.value);

76 if (isFinite(v) && v > 0) {

77 duration = v;

78 params.duration = v;

79 sim?.setDuration(v);

80 form.updateNotes();

81 updateButtons();

82 }

83 });

84 const u = document.createElement("span");

85 u.className = "unit";

86 u.textContent = "s";

87 durRow.append(l, durInput, u);

88 c.append(durRow, btnStart, btnPause, btnStop, btnContinue);

89 btnStart.addEventListener("click", () => void start());

90 btnPause.addEventListener("click", () => {

91 paused = !paused;

92 btnPause.textContent = paused ? "Resume" : "Pause";

93 if (!paused) void runLoop();

94 });

95 btnStop.addEventListener("click", () => {

96 if (!sim) return;

97 sim.stop();

98 paused = false;

99 btnPause.textContent = "Pause";

100 if (!running) {

101 setEditable(true);

102 updateButtons();

103 }

104 });

105 btnContinue.addEventListener("click", () => {

106 if (!sim) return;

107 sim.setDuration(duration);

108 if (sim.phase !== "done") void runLoop();

109 updateButtons();

110 });

111 updateButtons();

112}

113

114function updateButtons(): void {

115 const s = sim?.status();

116 btnStart.disabled = !device || !plate;

117 btnPause.disabled = !sim || s?.phase === "done" || (!running && !paused);

118 btnStop.disabled = !sim || s?.phase === "done";

119 btnContinue.disabled = !sim || running || !sim.canContinue();

120}

121

122function setEditable(enabled: boolean): void {

123 form.setEnabled(enabled);

124 editor.setEnabled(enabled);

125}

126

127// ---------- View toolbars ----------

128

129const viewMode = { value: "2d" as ViewMode };

130const colorSel = document.createElement("select");

131const scrub = document.createElement("input");

132const timeLabel = document.createElement("span");

133const btnLive = mkButton("Live");

134const btnDesign = mkButton("Design");

135const btnPlay = mkButton("Play");

136const btnWav = mkButton("Download .wav");

137const levelSel = document.createElement("select");

138const gainSlider = document.createElement("input");

139const gainLabel = document.createElement("span");

140const peakLabel = document.createElement("span");

141let exagInput: HTMLInputElement;

142let rangeInput: HTMLInputElement;

143let shapeCheck: HTMLInputElement;

144

145function gainDb(): number {

146 return parseFloat(gainSlider.value) || 0;

147}

148function levelMode(): LevelMode {

149 return levelSel.value as LevelMode;

150}

151

152function updateLevelReadout(): void {

153 gainLabel.textContent = `${gainDb() >= 0 ? "+" : ""}${gainDb()} dB`;

154 gainSlider.disabled = levelMode() !== "absolute";

155 if (!sim || sim.samples === 0) { peakLabel.textContent = ""; return; }

156 const audio = sim.recordedAudio();

157 const db = peakDbfs(audio, levelGain(audio, sim.fs, levelMode(), gainDb()));

158 peakLabel.textContent = isFinite(db) ? `peak ${db.toFixed(1)} dBFS${db > 0 ? " (clipped)" : ""}` : "";

159 peakLabel.className = db > 0 ? "warn" : "sub";

160 peakLabel.style.margin = "0";

161}

162

163function buildViewToolbar(): void {

164 const tb = $("viewToolbar");

165 const seg = document.createElement("span");

166 seg.className = "seg";

167 const b2 = mkButton("2D", "on"), b3 = mkButton("3D");

168 b2.addEventListener("click", () => { viewMode.value = "2d"; b2.classList.add("on"); b3.classList.remove("on"); });

169 b3.addEventListener("click", () => { viewMode.value = "3d"; b3.classList.add("on"); b2.classList.remove("on"); });

170 seg.append(b2, b3);

171 for (const [v, t] of [["field", "Height / displacement"], ["thickness", "Thickness"]]) {

172 const o = document.createElement("option");

173 o.value = v; o.textContent = t;

174 colorSel.appendChild(o);

175 }

176 exagInput = numInput(1, 0.5);

177 rangeInput = numInput(0, 0.5);

178 shapeCheck = document.createElement("input");

179 shapeCheck.type = "checkbox";

180 shapeCheck.checked = true;

181 shapeCheck.title = "Show the total shape (design profile plus vibration); unticked, only the vibration";

182 const hint = document.createElement("span");

183 hint.className = "sub";

184 hint.style.margin = "0";

185 hint.textContent = "3D: drag to orbit, wheel to zoom";

186 tb.append(seg, labeled("Color", colorSel), labeled("Exaggeration ×", exagInput), labeled("Color range (mm, 0 = auto)", rangeInput), labeled("Show profile", shapeCheck), hint);

187}

188

189function buildMovieToolbar(): void {

190 const tb = $("movieToolbar");

191 scrub.type = "range";

192 scrub.min = "0"; scrub.max = "0"; scrub.value = "0";

193 timeLabel.className = "time";

194 // Playback drives the movie; afterwards the view returns to where it was (live or scrubbed).

195 let liveBeforePlay = true;

196 const endPlayback = () => {

197 btnPlay.textContent = "Play";

198 if (liveBeforePlay) {

199 live = true;

200 updateLiveButton();

201 }

202 };

203 scrub.addEventListener("input", () => {

204 live = false;

205 liveBeforePlay = false;

206 previewMode = false;

207 scrubFrame = parseInt(scrub.value);

208 if (player.playing) player.stop();

209 updateLiveButton();

210 });

211 btnLive.addEventListener("click", () => { live = true; liveBeforePlay = true; previewMode = false; updateLiveButton(); });

212 btnDesign.title = "Show the design's stress-free shape instead of the simulation";

213 btnDesign.addEventListener("click", () => { showPreview(); updateLiveButton(); });

214 btnPlay.addEventListener("click", () => {

215 if (player.playing) { player.stop(); endPlayback(); return; }

216 if (!sim || sim.samples === 0) return;

217 liveBeforePlay = live;

218 const offset = live ? 0 : scrubFrame / sim.fps;

219 live = false;

220 previewMode = false;

221 player.play(sim.recordedAudio(), sim.fs, offset, levelMode(), gainDb());

222 btnPlay.textContent = "Stop";

223 updateLiveButton();

224 });

225 player.onEnded = endPlayback;

226 btnWav.addEventListener("click", () => {

227 if (!sim || sim.samples === 0) return;

228 const blob = encodeWav(sim.recordedAudio(), sim.fs, levelMode(), gainDb());

229 const a = document.createElement("a");

230 a.href = URL.createObjectURL(blob);

231 const name = sim.plate.name.replace(/[^a-z0-9]+/gi, "_").replace(/^_+|_+$/g, "").toLowerCase() || "cymbal";

232 a.download = `${name}_${(sim.samples / sim.fs).toFixed(1)}s_${sim.fs}Hz.wav`;

233 a.click();

234 setTimeout(() => URL.revokeObjectURL(a.href), 5000);

235 });

236 for (const [v, t] of [["absolute", "Absolute (0 dBFS = 1 Pa at 0 dB)"], ["loudness", "Loudness (RMS, soft clip)"], ["peak", "Peak"]]) {

237 const o = document.createElement("option");

238 o.value = v; o.textContent = t;

239 levelSel.appendChild(o);

240 }

241 gainSlider.type = "range";

242 gainSlider.min = "-40"; gainSlider.max = "60"; gainSlider.step = "1"; gainSlider.value = "20";

243 gainSlider.style.width = "120px";

244 gainSlider.style.flex = "none";

245 const restart = () => {

246 updateLevelReadout();

247 const pos = player.position();

248 if (pos !== null && sim) player.play(sim.recordedAudio(), sim.fs, pos, levelMode(), gainDb());

249 };

250 gainSlider.addEventListener("input", restart);

251 levelSel.addEventListener("change", restart);

252 tb.append(btnPlay, btnLive, btnDesign, scrub, timeLabel, labeled("Level", levelSel), labeled("Gain", gainSlider), gainLabel, peakLabel, btnWav);

253 updateLevelReadout();

254 updateLiveButton();

255}

256

257function updateLiveButton(): void {

258 btnLive.classList.toggle("on", live && !previewMode);

259 btnLive.disabled = !sim || (live && !previewMode);

260 btnDesign.classList.toggle("on", previewMode);

261 btnDesign.disabled = previewMode;

262}

263

264function buildSpecToolbar(): void {

265 const tb = $("specToolbar");

266 const win = document.createElement("select");

267 for (const n of [512, 1024, 2048, 4096, 8192]) {

268 const o = document.createElement("option");

269 o.value = String(n); o.textContent = String(n);

270 win.appendChild(o);

271 }

272 win.value = "2048";

273 const hop = numInput(512, 64);

274 const fmax = numInput(5000, 500);

275 const floor = numInput(80, 5);

276 const logf = document.createElement("input");

277 logf.type = "checkbox";

278 const apply = () => {

279 if (!sim) return;

280 spec.configure(

281 { windowSize: parseInt(win.value), hop: Math.max(16, parseInt(hop.value)), fmax: Math.min(sim.fs / 2, parseFloat(fmax.value)), dbFloor: parseFloat(floor.value), logFrequency: logf.checked },

282 sim.recordedAudio(), sim.samples,

283 );

284 };

285 for (const el of [win, hop, fmax, floor, logf]) el.addEventListener("change", apply);

286 tb.append(document.createTextNode("Spectrogram"), labeled("Window", win), labeled("Hop", hop), labeled("Max Hz", fmax), labeled("dB range", floor), labeled("Log freq.", logf));

287}

288

289function numInput(v: number, step: number): HTMLInputElement {

290 const i = document.createElement("input");

291 i.type = "number"; i.value = String(v); i.step = String(step);

292 return i;

293}

294function labeled(text: string, el: HTMLElement): HTMLLabelElement {

295 const l = document.createElement("label");

296 l.append(text, el);

297 return l;

298}

299

300// ---------- Design ----------

301

302/** Re-evaluates the current design at the current spacing and refreshes everything that depends on it. */

303function rebuildPlate(): void {

304 const design = editor.design;

305 plate = null;

306 plateError = editor.error;

307 if (design) {

308 try {

309 plate = evaluatePlate(design, params.spacing);

310 } catch (e) {

311 plateError = e instanceof DesignError ? e.message : String(e);

312 }

313 }

314 form.setPlate(plate);

315 editor.setStatus(plateError, plate ? designSummary(plate) : "");

316 showPreview();

317 updateButtons();

318}

319

320function fmtMm(v: number): string {

321 return `${(v * 1e3).toFixed(2)} mm`;

322}

323

324function designSummary(pl: Plate): string {

325 const g = pl.grid;

326 const hr = thicknessRange(pl);

327 const { mass } = massProperties(pl);

328 const { peakToPeak, maxSlope } = profileStats(pl);

329 const rows: [string, string][] = [

330 ["Design", pl.name],

331 ["Bounding box", `${fmtMm(pl.Lx)} × ${fmtMm(pl.Ly)} (${(pl.Lx / 0.0254).toFixed(1)} × ${(pl.Ly / 0.0254).toFixed(1)} in)`],

332 ["Material", `E ${(pl.mat.E / 1e9).toFixed(0)} GPa, ν ${pl.mat.nu}, ρ ${pl.mat.rho} kg/m³`],

333 ["Thickness", hr.min === hr.max ? fmtMm(hr.min) : `${fmtMm(hr.min)} to ${fmtMm(hr.max)} (mean ${fmtMm(hr.mean)})`],

334 ["Mass", `${(mass * 1e3).toFixed(0)} g`],

335 ["Grid", `${g.nx} × ${g.ny}, ${countInside(g)} nodes in the plate`],

336 ["Profile", peakToPeak > 0 ? `${fmtMm(peakToPeak)} peak to peak, largest slope ${maxSlope.toFixed(3)}` : "flat"],

337 ];

338 if (pl.mount) {

339 const mp = mountPatch(pl);

340 rows.push(["Mount", `${mp?.nodes.length ?? 0} nodes within ${fmtMm(pl.mount.radius)} of (${fmtMm(pl.mount.x)}, ${fmtMm(pl.mount.y)}); ${pl.mount.stiffness.toExponential(1)} N/m, ${pl.mount.damping} N s/m`]);

341 } else {

342 rows.push(["Mount", "none (free plate, inertia relief)"]);

343 }

344 rows.push(["Losses", `σ₀ ${pl.loss.sigma0} 1/s, σ₁ ${pl.loss.sigma1} m²/s, in-plane ${pl.loss.sigmaIn} 1/s`]);

345 let html = rows.map(([a, b]) => `<div class="row"><span>${a}</span><span>${b}</span></div>`).join("");

346 if (maxSlope > SLOPE_LIMIT) html += `<div class="warn">The largest slope of the profile, ${maxSlope.toFixed(2)}, is beyond the shallow-shell range of about ${SLOPE_LIMIT}; the bell or the bow is steeper than the model treats accurately.</div>`;

347 return html;

348}

349

350// ---------- Simulation control ----------

351

352async function start(): Promise<void> {

353 if (!device || !plate) return;

354 player.stop();

355 running = false;

356 await new Promise((r) => setTimeout(r, 0));

357 sim?.destroy();

358 spec.reset();

359 live = true;

360 paused = false;

361 btnPause.textContent = "Pause";

362 params.duration = duration;

363 try {

364 sim = new Simulation(device, plate, params);

365 } catch (e) {

366 $("info").innerHTML = `<div class="err">Could not start: ${String(e)}</div>`;

367 return;

368 }

369 const hr = thicknessRange(plate);

370 renderer?.setField(sim.grid, sim.w0, sim.nw, sim.hn, sim.w0Max, [hr.min, hr.max]);

371 previewMode = false;

372 movieBuf?.destroy();

373 movieBuf = device.createBuffer({ size: Math.max(16, sim.grid.n * 4), usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST });

374 movieBufFrame = -1;

375 scrub.max = "0"; scrub.value = "0";

376 lastStatsTime = performance.now(); lastStatsSteps = 0; stepsPerSec = 0;

377 setEditable(false);

378 updateLiveButton();

379 void runLoop();

380}

381

382async function runLoop(): Promise<void> {

383 if (!sim || running) return;

384 running = true;

385 updateButtons();

386 try {

387 while (sim.phase !== "done" && !paused) {

388 await sim.runBatch();

389 spec.update(sim.recordedAudio(), sim.samples);

390 scrub.max = String(Math.max(0, sim.frames.length - 1));

391 if (live) scrub.value = scrub.max;

392 updateLevelReadout();

393 const now = performance.now();

394 if (now - lastStatsTime > 500) {

395 stepsPerSec = ((sim.totalSteps - lastStatsSteps) * 1000) / (now - lastStatsTime);

396 lastStatsTime = now; lastStatsSteps = sim.totalSteps;

397 }

398 }

399 } catch (e) {

400 console.error(e);

401 $("info").innerHTML = `<div class="err">Simulation error: ${String(e)}</div>`;

402 }

403 running = false;

404 if (sim.phase === "done") setEditable(true);

405 updateButtons();

406}

407

408// ---------- Render loop ----------

409

410let frameErrorShown = false;

411let lastRenderKey = "";

412let lastInfoHtml = "";

413

414function frame(): void {

415 requestAnimationFrame(frame);

416 try {

417 frameBody();

418 } catch (e) {

419 if (!frameErrorShown) { frameErrorShown = true; console.error("frame exception:", e); }

420 }

421}

422

423function markers(pl: Plate): void {

424 if (!renderer) return;

425 const [sx, sy] = strikePoint(params, pl);

426 renderer.strike = { x: sx, y: sy, r: params.contactRadius };

427 renderer.mount = pl.mount ? { x: pl.mount.x, y: pl.mount.y, r: pl.mount.radius } : null;

428}

429

430function frameBody(): void {

431 if (!device || !renderer) return;

432 renderer.mode = viewMode.value;

433 renderer.colorMode = colorSel.value as ColorMode;

434 renderer.exaggeration = parseFloat(exagInput.value) || 1;

435 renderer.colorRange = (parseFloat(rangeInput.value) || 0) * 1e-3;

436 renderer.showShape = shapeCheck.checked;

437 const canvas = $<HTMLCanvasElement>("view");

438 const cam = renderer.camera;

439 const viewKey = [

440 renderer.mode, renderer.colorMode, renderer.exaggeration, renderer.colorRange, renderer.showShape,

441 cam.yaw.toFixed(4), cam.pitch.toFixed(4), cam.dist.toFixed(4),

442 canvas.clientWidth, canvas.clientHeight, window.devicePixelRatio,

443 params.strikeFracX, params.strikeFracY, params.contactRadius,

444 ];

445 if (previewMode || !sim) {

446 // The stress-free shape of the design that the next Start will use.

447 ensurePreview(device);

448 const renderKey = ["preview", ...viewKey, preview?.plate.name, preview?.plate.grid.n].join("|");

449 if (renderKey !== lastRenderKey) {

450 lastRenderKey = renderKey;

451 renderPreview(device);

452 }

453 if (sim) {

454 spec.draw($("spec"), sim.fs, Math.max(duration, sim.samples / sim.fs), null);

455 updateInfo(sim.status());

456 }

457 return;

458 }

459 const pos = player.position();

460 if (pos !== null) {

461 scrubFrame = Math.min(sim.frames.length - 1, Math.floor(pos * sim.fps));

462 scrub.value = String(scrubFrame);

463 }

464 const st = sim.status();

465 // Render only when something visible changed, so an idle or paused page does no work.

466 const renderKey = [...viewKey, live, scrubFrame, sim.frames.length, st.totalSteps, st.phase].join("|");

467 if (renderKey !== lastRenderKey) {

468 lastRenderKey = renderKey;

469 renderView(device, st);

470 }

471 spec.draw($("spec"), sim.fs, Math.max(duration, sim.samples / sim.fs), pos ?? (live ? null : scrubFrame / sim.fps));

472 updateInfo(st);

473}

474

475/** Builds the preview buffers from the current plate when they are missing or stale. */

476function ensurePreview(dev: GPUDevice): void {

477 if (preview && !preview.stale) return;

478 if (!plate) return;

479 if (preview) for (const b of [preview.w0, preview.zero, preview.nw, preview.hn]) b.destroy();

480 const grid = plate.grid;

481 const shape = Float32Array.from(plate.w0);

482 let wmax = 0;

483 for (let k = 0; k < shape.length; k++) wmax = Math.max(wmax, Math.abs(shape[k]));

484 const mk = (data: Float32Array<ArrayBuffer>) => {

485 const b = dev.createBuffer({ size: Math.max(16, data.byteLength), usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_DST });

486 dev.queue.writeBuffer(b, 0, data);

487 return b;

488 };

489 preview = { plate, w0: mk(shape), zero: mk(new Float32Array(grid.n)), nw: mk(nodeWeights(grid)), hn: mk(Float32Array.from(plate.h)), wmax, stale: false };

490 const hr = thicknessRange(plate);

491 renderer?.setField(grid, preview.zero, preview.nw, preview.hn, 0, [hr.min, hr.max]);

492 lastRenderKey = "";

493}

494

495/** Marks the preview stale (the design or the spacing changed) and shows it; the next frame rebuilds it. */

496function showPreview(): void {

497 if (preview) preview.stale = true;

498 previewMode = true;

499 updateLiveButton();

500 if (!sim) updateIdleInfo();

501}

502

503function renderPreview(dev: GPUDevice): void {

504 if (!renderer || !preview) return;

505 // The renderer's "initial shape" buffer is zero here, and the shape itself is the displayed field.

506 if (renderer.fieldGrid !== preview.plate.grid) {

507 const hr = thicknessRange(preview.plate);

508 renderer.setField(preview.plate.grid, preview.zero, preview.nw, preview.hn, 0, [hr.min, hr.max]);

509 }

510 markers(preview.plate);

511 const enc = dev.createCommandEncoder();

512 renderer.render(enc, preview.w0, preview.wmax);

513 timeLabel.textContent = "design";

514 dev.pushErrorScope("validation");

515 dev.queue.submit([enc.finish()]);

516 void dev.popErrorScope().then((e) => { if (e && !frameErrorShown) { frameErrorShown = true; console.error("frame validation error:", e.message); } });

517}

518

519function updateIdleInfo(): void {

520 const html = plate

521 ? `<p class="sub">The view shows the design's stress-free shape. Press Start to strike it.</p>`

522 : `<p class="err">${plateError ?? "No design."}</p>`;

523 if (html !== lastInfoHtml) {

524 lastInfoHtml = html;

525 $("info").innerHTML = html;

526 }

527}

528

529function renderView(dev: GPUDevice, st: SimStatus): void {

530 if (!sim || !renderer) return;

531 if (renderer.fieldGrid !== sim.grid) {

532 const hr = thicknessRange(sim.plate);

533 renderer.setField(sim.grid, sim.w0, sim.nw, sim.hn, sim.w0Max, [hr.min, hr.max]);

534 }

535 markers(sim.plate);

536 const enc = dev.createCommandEncoder();

537 if (live || sim.frames.length === 0) {

538 sim.encodeDisplay(enc);

539 renderer.render(enc, sim.displayW, st.wmax);

540 timeLabel.textContent = `${st.t.toFixed(3)} s`;

541 } else {

542 const f = Math.max(0, Math.min(sim.frames.length - 1, scrubFrame));

543 if (movieBufFrame !== f) {

544 dev.queue.writeBuffer(movieBuf!, 0, sim.frames[f]);

545 movieBufFrame = f;

546 }

547 let wmax = 0;

548 const fr = sim.frames[f];

549 for (let k = 0; k < fr.length; k += 7) wmax = Math.max(wmax, Math.abs(fr[k]));

550 renderer.render(enc, movieBuf!, wmax);

551 timeLabel.textContent = `${(f / sim.fps).toFixed(3)} s`;

552 }

553 dev.pushErrorScope("validation");

554 dev.queue.submit([enc.finish()]);

555 void dev.popErrorScope().then((e) => { if (e && !frameErrorShown) { frameErrorShown = true; console.error("frame validation error:", e.message); } });

556}

557

558function updateInfo(st: SimStatus): void {

559 if (!sim) return;

560 const g = sim.grid;

561 const spl = st.peakPressure > 0 ? 20 * Math.log10(st.peakPressure / 2e-5) : -Infinity;

562 const rows: [string, string][] = [

563 ["Design", sim.plate.name],

564 ["Phase", st.phase === "done" ? "done" : "ringing (recording)"],

565 ["Time", `${st.t.toFixed(3)} s`],

566 ["Grid", `${g.nx} × ${g.ny} nodes (${countInside(g)} in the plate), ${(g.hx * 1e3).toFixed(2)} × ${(g.hy * 1e3).toFixed(2)} mm`],

567 ["Time step", `${(sim.dt * 1e6).toFixed(3)} µs (${sim.stepsPerSample} per sample)`],

568 ["Speed", `${(stepsPerSec / 1e3).toFixed(0)} k steps/s (${(stepsPerSec * sim.dt).toFixed(3)}× real time)`],

569 ["Kinetic energy", `${st.ke.toExponential(2)} J`],

570 ["Max |w|", `${(st.wmax * 1e3).toFixed(3)} mm`],

571 ["Audio", `${(st.samples / sim.fs).toFixed(2)} s, ${st.frames} frames`],

572 ["Peak pressure", st.peakPressure > 0 ? `${st.peakPressure.toFixed(3)} Pa (${spl.toFixed(1)} dB SPL)` : "–"],

573 ["Stick", `${(st.stick.x * 1e3).toFixed(2)} mm, ${st.stick.v.toFixed(2)} m/s`],

574 ["Contact force", `${st.stick.force.toFixed(1)} N (max ${st.stick.maxForce.toFixed(1)} N)`],

575 ];

576 let html = rows.map(([a, b]) => `<div class="row"><span>${a}</span><span>${b}</span></div>`).join("");

577 if (st.delayClamped) html += `<div class="warn">The listener is so close that some propagation delays were clamped.</div>`;

578 if (!isFinite(st.wmax) || st.wmax > 1) html += `<div class="err">The solution has diverged. Increase the grid spacing (which lengthens the time step) or reduce the strike.</div>`;

579 if (html !== lastInfoHtml) {

580 lastInfoHtml = html;

581 $("info").innerHTML = html;

582 }

583}

584

585// ---------- Self-test ----------

586

587let selfTestResult: { done: boolean; passed?: boolean; cases?: SelfTestCase[]; error?: string } = { done: false };

588

589async function selfTest(): Promise<void> {

590 if (!device) { selfTestResult = { done: true, passed: false, error: "no GPU device" }; return; }

591 $("info").innerHTML = `<p class="sub">Running the GPU-versus-CPU self-test...</p>`;

592 try {

593 const cases = await runSelfTest(device);

594 const passed = cases.every(selfTestPassed);

595 selfTestResult = { done: true, passed, cases };

596 const rows = cases.map((c) => `<div class="row"><span>${c.name}</span><span class="${selfTestPassed(c) ? "" : "err"}">acc ${c.accError.u.toExponential(1)} / ${c.accError.v.toExponential(1)} / ${c.accError.w.toExponential(1)}, pos ${c.positionError.toExponential(1)}</span></div>`);

597 $("info").innerHTML = `<div class="${passed ? "row" : "err"}">Self-test ${passed ? "passed" : "FAILED"}</div>${rows.join("")}<p class="sub">Maximum relative errors of the u, v, w accelerations and of the compensated w update, GPU step versus float64 reference.</p>`;

598 } catch (e) {

599 selfTestResult = { done: true, passed: false, error: String(e) };

600 $("info").innerHTML = `<div class="err">Self-test error: ${String(e)}</div>`;

601 }

602}

603

604// ---------- Init ----------

605

606async function init(): Promise<void> {

607 editor = new DesignEditor($("design"));

608 form = new ParamForm($("params"), params);

609 form.onChange = (key, isLive) => {

610 if (key === "spacing") { rebuildPlate(); return; }

611 if (!isLive) { showPreview(); return; }

612 if (!sim) return;

613 if (key.startsWith("listener")) sim.setListener(params.listenerDist, params.listenerAzimuth, params.listenerElevation);

614 };

615 editor.onDesign = () => rebuildPlate();

616 buildControls();

617 buildViewToolbar();

618 buildMovieToolbar();

619 buildSpecToolbar();

620 const q = new URLSearchParams(location.search);

621 const set = form.applyUrl(q);

622 if (set.includes("duration")) {

623 duration = params.duration;

624 durInput.value = String(duration);

625 }

626 const presetId = q.get("preset");

627 const preset = presetId ? PRESETS.find((p) => p.id === presetId) : null;

628 if (preset) editor.setScript(preset.source, preset.id);

629 else editor.compileNow();

630 exposeHooks();

631 if (!("gpu" in navigator)) {

632 showNoGpu("WebGPU is not available in this browser. Use a recent Chrome or Edge, or Firefox or Safari with WebGPU enabled.");

633 return;

634 }

635 const adapter = (await navigator.gpu.requestAdapter({ powerPreference: "high-performance" })) ?? (await navigator.gpu.requestAdapter());

636 if (!adapter) {

637 showNoGpu("No WebGPU adapter was found.");

638 return;

639 }

640 device = await adapter.requestDevice();

641 device.lost.then((info) => showNoGpu(`WebGPU device lost: ${info.message}`));

642 device.addEventListener("uncapturederror", (ev) => console.error("WebGPU error:", (ev as GPUUncapturedErrorEvent).error.message));

643 renderer = new Renderer(device, $("view"));

644 updateIdleInfo();

645 updateButtons();

646 requestAnimationFrame(frame);

647 if (q.get("selftest") === "1") await selfTest();

648 else if (q.get("autostart") === "1") void start();

649}

650

651/** Hooks for automated tests, on window.steelsim. */

652function exposeHooks(): void {

653 (window as unknown as { steelsim: unknown }).steelsim = {

654 status: () => (sim ? { ...sim.status(), dt: sim.dt, stepsPerSample: sim.stepsPerSample, nx: sim.grid.nx, ny: sim.grid.ny, stepsPerSec } : null),

655 audio: () => (sim ? Array.from(sim.recordedAudio()) : null),

656 frames: () => sim?.frames.length ?? 0,

657 design: () => (plate ? { name: plate.name, nodes: countInside(plate.grid), mounted: !!plate.mount, error: null } : { name: null, nodes: 0, mounted: false, error: plateError }),

658 setScript: (source: string) => editor.setScript(source),

659 start: () => void start(),

660 selftest: () => selfTestResult,

661 noGpu: () => { const e = $("nogpu"); return e.hidden ? null : e.textContent; },

662 };

663}

664

665function showNoGpu(msg: string): void {

666 const el = $("nogpu");

667 el.hidden = false;

668 el.textContent = msg;

669 btnStart.disabled = true;

670 selfTestResult = { done: true, passed: false, error: msg };

671}

672

673void init();