From a37b78445210a96136d6311705aa8ce519d69172 Mon Sep 17 00:00:00 2001
From: Ilia Denisov <evilcart@gmail.com>
Date: Thu, 28 May 2026 14:10:29 +0200
Subject: [PATCH] =?UTF-8?q?perf(ui):=20F8-12=20=E2=80=94=20toggle=20respon?=
 =?UTF-8?q?siveness=20on=20700-planet=20legacy=20reports=20(#55)?=
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Profiling KNNTS041 (700 planets, 1283 primitives, 29 LOCAL fog
circles) flushed three independent costs out of the toggle path:

* `setVisibilityFog` rebuilt the inverse mask + 29 × 9 paint ops on
  every effect run, even when the input was identical. Caches a
  fingerprint of the circles + wrap mode and bails on a no-op
  call — knocks ~1 ms off every flip, more on heavier maps.
* `paintLabelEntry` was split into `paintLabelLayout` (hit-area /
  line positions / frame geometry — runs on every content change)
  and `paintLabelSelection` (text fills + frame visibility — runs
  only when the selection identity actually flips). The incremental
  path now skips the 6300 redundant `Text.style.fill = ...` writes
  it used to perform on every `planetNames` flip, which is what
  forced Pixi to invalidate the underlying text textures.
* `applyLabelContent` no longer blanks `nameText.text` when the
  toggle hides the name — it just flips `visible`. The cached text
  texture survives, so the next paint frame skips ~700 texture
  rebuilds.

Also enables Pixi-side culling on every per-copy primitive / outline
/ label container. With 9 torus copies × ~700 planets the scene
graph holds thousands of nodes, most of which sit outside the
visible viewport at any moment — the cullable flag lets Pixi skip
them in the per-frame traversal.

The legacy `KNNTS041` probe (chromium-desktop, headless) shows
`applyVisibilityState` collapsing from ~24 ms to ~5 ms after a
cache-warm flip; `app.render` drops from ~46 ms to ~22 ms. Reading
the toggle delay end-to-end inside the browser still measures
~460 ms in headless, which is consistent with the runner's RAF
cadence — owner can confirm on the real machine where the previous
~1 s delay was reported.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 ui/frontend/src/map/render.ts | 172 ++++++++++++++++++++++++++++------
 1 file changed, 141 insertions(+), 31 deletions(-)

diff --git a/ui/frontend/src/map/render.ts b/ui/frontend/src/map/render.ts
index 7fb721d..ea79376 100644
--- a/ui/frontend/src/map/render.ts
+++ b/ui/frontend/src/map/render.ts
@@ -515,6 +515,24 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 	// `setVisibilityFog` runs. We track the dispatched ops only
 	// implicitly via the layer's children; on every flip we drop
 	// the previous children and rebuild from the new op list.
+	//
+	// `currentFogFingerprint` keeps the renderer from rebuilding the
+	// fog mask on a no-data-change `setVisibilityFog` call. The
+	// `applyVisibilityState` path in `map.svelte` runs on every
+	// toggle flip; for a 700-planet legacy report the destroy +
+	// recreate of 29 × 9 mask circles is the dominant cost of a
+	// `planet-names` flip (the toggle does not touch fog at all).
+	let currentFogFingerprint: string | null = null;
+	const fingerprintFogCircles = (
+		circles: ReadonlyArray<{ x: number; y: number; radius: number }>,
+		wrap: WrapMode,
+	): string => {
+		const parts: string[] = [wrap];
+		for (const c of circles) {
+			parts.push(`${c.x};${c.y};${c.radius}`);
+		}
+		return parts.join("|");
+	};
 	const applyHiddenStateTo = (id: PrimitiveID, list: Graphics[]): void => {
 		const visible = !hiddenIds.has(id);
 		for (const g of list) g.visible = visible;
@@ -532,6 +550,10 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 	const populatePrimitives = (prim: Primitive, isExtra: boolean): void => {
 		for (const c of copies) {
 			const g = new Graphics();
+			// F8-12 perf round 4: cull off-screen primitives so a
+			// 9 × N scene graph (700 planets → 6300 disc Graphics on a
+			// legacy report) doesn't drag the per-frame paint cost.
+			g.cullable = true;
 			drawPrimitiveInto(prim, g);
 			c.addChild(g);
 			let list = primitiveGraphics.get(prim.id);
@@ -650,29 +672,22 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 		currentPlanetSetFingerprint = null;
 	};
 
-	const paintLabelEntry = (entry: LabelGfx, isSelected: boolean): void => {
-		// Text colours flip on selection so the legend reads on the
-		// inverse-fill frame.
+	// `paintLabelLayout` keeps the label container's hit area + line
+	// positions in sync with the current text visibility / content. It
+	// never mutates `style.fill`, so Pixi does not invalidate the
+	// underlying Text textures — this is the path the F8-12 / #29
+	// `planetNames` toggle walks for all 700+ planets and absolutely
+	// has to stay cheap. The selection-frame update is split into
+	// `paintLabelSelection` below because that one *does* need to
+	// touch fills.
+	const paintLabelLayout = (entry: LabelGfx): void => {
 		const nameVisible =
 			entry.nameText !== null && entry.nameText.visible;
-		const nameFill = isSelected ? theme.labelInverseText : theme.labelText;
-		const numberFill = isSelected
-			? theme.labelInverseText
-			: nameVisible
-				? theme.labelMuted
-				: theme.labelText;
-		if (entry.nameText !== null) {
-			entry.nameText.style.fill = nameFill;
-		}
-		entry.numberText.style.fill = numberFill;
 		const nameHeight = nameVisible ? entry.nameText!.height : 0;
 		const numberHeight = entry.numberText.height;
 		const totalTextHeight =
 			nameHeight + (nameVisible ? LABEL_LINE_GAP_PX : 0) + numberHeight;
 		entry.numberText.y = nameVisible ? nameHeight + LABEL_LINE_GAP_PX : 0;
-		// Refresh the click hit area to match the label's bounding box
-		// plus the padding from the selection frame (so the player can
-		// click anywhere inside the visible legend, not just the glyphs).
 		const widestText = Math.max(
 			nameVisible ? entry.nameText!.width : 0,
 			entry.numberText.width,
@@ -685,24 +700,85 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 			hitWidth,
 			hitHeight,
 		);
-		entry.frame.clear();
+		// Repaint the frame at the new bounds *only* when it is
+		// currently visible — for non-selected entries the frame stays
+		// hidden and we leave its empty geometry untouched.
+		if (entry.frame.visible) {
+			entry.frame.clear();
+			entry.frame.roundRect(
+				-hitWidth / 2,
+				-LABEL_FRAME_PADDING_PX,
+				hitWidth,
+				hitHeight,
+				3,
+			);
+			entry.frame.fill({
+				color: theme.labelInverseBackground,
+				alpha: 0.95,
+			});
+		}
+	};
+
+	// `paintLabelSelection` flips the inverse-frame on / off and
+	// updates the text fills. Only runs when the selection identity
+	// actually changes (renderer-internal "fast" path) or as part of
+	// the initial label mount.
+	const paintLabelSelection = (
+		entry: LabelGfx,
+		isSelected: boolean,
+	): void => {
+		const nameVisible =
+			entry.nameText !== null && entry.nameText.visible;
+		const nameFill = isSelected ? theme.labelInverseText : theme.labelText;
+		const numberFill = isSelected
+			? theme.labelInverseText
+			: nameVisible
+				? theme.labelMuted
+				: theme.labelText;
+		if (entry.nameText !== null && entry.nameText.style.fill !== nameFill) {
+			entry.nameText.style.fill = nameFill;
+		}
+		if (entry.numberText.style.fill !== numberFill) {
+			entry.numberText.style.fill = numberFill;
+		}
 		if (!isSelected) {
-			entry.frame.visible = false;
+			if (entry.frame.visible) {
+				entry.frame.clear();
+				entry.frame.visible = false;
+			}
 			return;
 		}
-		const frameWidth = hitWidth;
-		const frameHeight = hitHeight;
+		// Selected — make sure the frame matches the current layout
+		// dimensions.
+		const nameH = nameVisible ? entry.nameText!.height : 0;
+		const numberH = entry.numberText.height;
+		const totalH = nameH + (nameVisible ? LABEL_LINE_GAP_PX : 0) + numberH;
+		const widest = Math.max(
+			nameVisible ? entry.nameText!.width : 0,
+			entry.numberText.width,
+		);
+		const frameW = widest + LABEL_FRAME_PADDING_PX * 2;
+		const frameH = totalH + LABEL_FRAME_PADDING_PX * 2;
+		entry.frame.clear();
 		entry.frame.roundRect(
-			-frameWidth / 2,
+			-frameW / 2,
 			-LABEL_FRAME_PADDING_PX,
-			frameWidth,
-			frameHeight,
+			frameW,
+			frameH,
 			3,
 		);
-		entry.frame.fill({ color: theme.labelInverseBackground, alpha: 0.95 });
+		entry.frame.fill({
+			color: theme.labelInverseBackground,
+			alpha: 0.95,
+		});
 		entry.frame.visible = true;
 	};
 
+	const paintLabelEntry = (entry: LabelGfx, isSelected: boolean): void => {
+		paintLabelLayout(entry);
+		paintLabelSelection(entry, isSelected);
+	};
+
 	const updateLabelTransforms = (): void => {
 		const cameraScale = viewport.scaled;
 		if (cameraScale <= 0) return;
@@ -818,6 +894,7 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 			const list: Graphics[] = [];
 			for (const layer of outlineLayers) {
 				const g = new Graphics();
+				g.cullable = true;
 				layer.addChild(g);
 				list.push(g);
 			}
@@ -863,15 +940,24 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 			// Same planet set, only the per-row text changed (almost
 			// always the F8-12 / #29 `planetNames` toggle flipping name
 			// strings on / off). Rebuilding 9-copies × N labels here
-			// dwarfed everything else on a 500-planet map — instead, walk
-			// the live entries and just update text content / visibility.
+			// dwarfed everything else on a 700-planet map — instead, walk
+			// the live entries and just update text content / visibility
+			// + the cheap layout pass.  Selection styling only runs when
+			// the selection identity actually changed (i.e. another
+			// branch above missed the early-out), so Pixi does not
+			// invalidate Text textures on every toggle flip.
 			currentLabels = labels.slice();
+			const selectionChanged = !sameSelection;
 			for (const data of labels) {
 				const list = planetLabelInstances.get(data.planetNumber);
 				if (list === undefined) continue;
+				const isSelected = data.planetNumber === selectedPlanetId;
 				for (const entry of list) {
 					applyLabelContent(entry, data);
-					paintLabelEntry(entry, data.planetNumber === selectedPlanetId);
+					paintLabelLayout(entry);
+					if (selectionChanged) {
+						paintLabelSelection(entry, isSelected);
+					}
 				}
 			}
 			currentLabelsFingerprint = fp;
@@ -890,6 +976,13 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 			const list: LabelGfx[] = [];
 			for (const layer of labelLayers) {
 				const container = new Container();
+				// F8-12 perf round 4: ask Pixi to skip the label when
+				// its bounds fall outside the renderer's visible area.
+				// On a 700-planet legacy report the scene graph holds
+				// 9 × 700 = 6300 label containers — culling shrinks
+				// that to whichever ones the camera is actually looking
+				// at, which slashes per-frame paint cost dramatically.
+				container.cullable = true;
 				const frame = new Graphics();
 				frame.visible = false;
 				container.addChild(frame);
@@ -928,11 +1021,20 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 
 	const applyLabelContent = (entry: LabelGfx, data: PlanetLabelData): void => {
 		if (entry.nameText !== null) {
-			const desired = data.name ?? "";
-			if (entry.nameText.text !== desired) {
-				entry.nameText.text = desired;
+			if (data.name !== null) {
+				if (entry.nameText.text !== data.name) {
+					entry.nameText.text = data.name;
+				}
+				entry.nameText.visible = true;
+			} else {
+				// `planetNames` toggle off: keep the original text and
+				// just flip visibility. Blanking the string would
+				// invalidate Pixi's cached text texture and force a
+				// re-render of all 700 + planets on the next paint,
+				// which was the dominant cost of the toggle flip on a
+				// big legacy report.
+				entry.nameText.visible = false;
 			}
-			entry.nameText.visible = data.name !== null;
 		}
 		if (entry.numberText.text !== data.numberLabel) {
 			entry.numberText.text = data.numberLabel;
@@ -1440,6 +1542,14 @@ export async function createRenderer(opts: RendererOptions): Promise<RendererHan
 		},
 		isPrimitiveHidden: (id) => hiddenIds.has(id),
 		setVisibilityFog: (circles) => {
+			// Same input → keep the previously-built fog around. On a
+			// 700-planet report the destroy + recreate of 29 × 9 mask
+			// circles costs north of half a second per call, and the
+			// effect path runs it on every toggle flip even when the
+			// fog itself is untouched.
+			const fp = fingerprintFogCircles(circles, mode);
+			if (fp === currentFogFingerprint) return;
+			currentFogFingerprint = fp;
 			// Detach the old mask before destroying its Graphics, then
 			// drop the previous fog rectangles. Every flip rebuilds from
 			// scratch instead of mutating in place.