perf: skip sunburst boundary sampling during animation

.changeset/sunburst-path-projection.md

@@ -0,0 +1,5 @@
+---
+'@tanstack/charts': patch
+---
+
+Avoid rebuilding sunburst hit-test boundaries when projecting animation frames.

benchmarks/comparison/bundle-baseline.json

@@ -1,6 +1,6 @@
 {
   "schemaVersion": 4,
-  "generatedAt": "2026-10-13T23:35:26.997Z",
+  "generatedAt": "2026-10-14T02:03:21.704Z",
   "packageVersions": {
     "tanstack": "1.1.0",
     "chartjs": "4.5.1",
@@ -11,8 +11,8 @@
   "sources": {
     "tanstack": {
       "kind": "workspace",
-      "revision": "a691036b07655adda97aa0dc3052428989e2b811",
-      "inputDigest": "sha256:390854b69e6ac7c4453ba8bcc75dfd5240f70bbd9f69efdc8d25c7fba528d951"
+      "revision": "cd2a8a7fcab201ca32db60ca6d6c8e92c4dd47b8",
+      "inputDigest": "sha256:6c5dc96470c53874d724ca231e9e5a552800d04834e584260cc2eac4b504974e"
     },
     "chartjs": {
       "kind": "package",

benchmarks/conformance/previews/manifest.json

@@ -2,7 +2,7 @@
   "schemaVersion": 1,
   "width": 288,
   "height": 192,
-  "sourceHash": "82eecd6c1fbdca5e857b965e09bb53c550520b2e596fbc4e9850266f03fdb9b4",
+  "sourceHash": "9bbb0210cda37cf492ff11d793f0e23d493f9aebc849609518fa4abc1ce7a26a",
   "assets": [
     {
       "id": "01-line-gaps",

docs/comparison.md

@@ -12,14 +12,14 @@ turning untested behavior into a checkmark.
 
 | Library                                                                                | Package              | Measured source     |
 | -------------------------------------------------------------------------------------- | -------------------- | ------------------- |
-| [TanStack Charts](./overview.md)                                                       | `@tanstack/charts`   | workspace `a691036` |
+| [TanStack Charts](./overview.md)                                                       | `@tanstack/charts`   | workspace `cd2a8a7` |
 | [Chart.js](https://www.chartjs.org/docs/latest/)                                       | `chart.js`           | npm `4.5.1`         |
 | [Apache ECharts](https://echarts.apache.org/handbook/en/best-practices/canvas-vs-svg/) | `echarts`            | npm `6.1.0`         |
 | [Recharts](https://recharts.github.io/en-US/)                                          | `recharts`           | npm `3.10.1`        |
 | [Observable Plot](https://observablehq.com/plot/features/plots)                        | `@observablehq/plot` | npm `0.6.17`        |
 
 The competitor versions are exact package pins, not latest versions inferred
-at page render time. The measured TanStack workspace revision is `a691036`.
+at page render time. The measured TanStack workspace revision is `cd2a8a7`.
 
 ## Capability matrix
 
@@ -90,7 +90,7 @@ output model.
 
 ## Bundle snapshot
 
-Baseline date: `2026-10-13`.
+Baseline date: `2026-10-14`.
 
 Controlled ranges cover 12 independently built, minified browser consumers:
 line, bar, area, and scatter at basic, interactive, and advanced tiers. Only

packages/charts-core/docs/comparison.md

@@ -12,14 +12,14 @@ turning untested behavior into a checkmark.
 
 | Library                                                                                | Package              | Measured source     |
 | -------------------------------------------------------------------------------------- | -------------------- | ------------------- |
-| [TanStack Charts](./overview.md)                                                       | `@tanstack/charts`   | workspace `a691036` |
+| [TanStack Charts](./overview.md)                                                       | `@tanstack/charts`   | workspace `cd2a8a7` |
 | [Chart.js](https://www.chartjs.org/docs/latest/)                                       | `chart.js`           | npm `4.5.1`         |
 | [Apache ECharts](https://echarts.apache.org/handbook/en/best-practices/canvas-vs-svg/) | `echarts`            | npm `6.1.0`         |
 | [Recharts](https://recharts.github.io/en-US/)                                          | `recharts`           | npm `3.10.1`        |
 | [Observable Plot](https://observablehq.com/plot/features/plots)                        | `@observablehq/plot` | npm `0.6.17`        |
 
 The competitor versions are exact package pins, not latest versions inferred
-at page render time. The measured TanStack workspace revision is `a691036`.
+at page render time. The measured TanStack workspace revision is `cd2a8a7`.
 
 ## Capability matrix
 
@@ -90,7 +90,7 @@ output model.
 
 ## Bundle snapshot
 
-Baseline date: `2026-10-13`.
+Baseline date: `2026-10-14`.
 
 Controlled ranges cover 12 independently built, minified browser consumers:
 line, bar, area, and scatter at basic, interactive, and advanced tiers. Only

packages/charts-core/src/hierarchy-sunburst.ts

@@ -10,7 +10,7 @@ import {
 } from './hierarchy-flat-internal'
 import { channelValues, isChartKey, isFiniteNumber, visualValue } from './mark'
 import { createPolarMark } from './polar-mark-internal'
-import { resolvePolarSector } from './polar-sector-internal'
+import { projectPolarSector, resolvePolarSector } from './polar-sector-internal'
 import {
   sceneMotionNode,
   type SceneMotionMetadata,
@@ -340,22 +340,13 @@ export function sunburst<TDatum>(
 }
 
 function projectSunburstSectorPath(values: readonly number[]) {
-  const [startAngle, endAngle, innerRadius, outerRadius] = values
-  if (
-    startAngle === undefined ||
-    endAngle === undefined ||
-    innerRadius === undefined ||
-    outerRadius === undefined
-  ) {
-    return undefined
-  }
-  return resolvePolarSector({
-    startAngle,
-    endAngle,
-    innerRadius,
-    outerRadius,
+  return projectPolarSector({
+    startAngle: values[0]!,
+    endAngle: values[1]!,
+    innerRadius: values[2]!,
+    outerRadius: values[3]!,
     cornerRadius: 0,
-  })?.path
+  })
 }
 
 function sunburstNodeContext<TDatum>(

packages/charts-core/src/polar-sector-internal.test.ts

@@ -0,0 +1,56 @@
+import { describe, expect, it, vi } from 'vitest'
+import { projectPolarSector, resolvePolarSector } from './polar-sector-internal'
+
+describe('polar sector projection', () => {
+  it.each([
+    [0, 2, 20, 60, 0],
+    [2, -3, 80, 40, 8],
+    [0, Math.PI * 2, 0, 80, 6],
+    [0, 0.012, 60, 80, 6],
+  ])(
+    'keeps the rendered path without sampling its boundary: %j',
+    (...values) => {
+      const [startAngle, endAngle, innerRadius, outerRadius, cornerRadius] =
+        values
+      const sector = {
+        startAngle: startAngle!,
+        endAngle: endAngle!,
+        innerRadius: innerRadius!,
+        outerRadius: outerRadius!,
+        cornerRadius: cornerRadius!,
+      }
+      const cosine = vi.spyOn(Math, 'cos')
+      try {
+        const projected = projectPolarSector(sector)
+        const projectionCalls = cosine.mock.calls.length
+        cosine.mockClear()
+        const resolved = resolvePolarSector(sector)
+        expect(resolved?.path).toBe(projected)
+        expect(resolved!.points.length).toBeGreaterThan(0)
+        expect(cosine.mock.calls.length).toBeGreaterThan(projectionCalls)
+        expect(projectPolarSector(sector)).toBe(projected)
+      } finally {
+        cosine.mockRestore()
+      }
+    },
+  )
+
+  it.each([
+    'startAngle',
+    'endAngle',
+    'innerRadius',
+    'outerRadius',
+    'cornerRadius',
+  ] as const)('still rejects nonfinite %s', (field) => {
+    const sector = {
+      startAngle: 0,
+      endAngle: 2,
+      innerRadius: 20,
+      outerRadius: 60,
+      cornerRadius: 0,
+      [field]: Number.NaN,
+    }
+    expect(projectPolarSector(sector)).toBeUndefined()
+    expect(resolvePolarSector(sector)).toBeUndefined()
+  })
+})

packages/charts-core/src/polar-sector-internal.ts

@@ -19,10 +19,7 @@ export interface ResolvedPolarSector {
 
 let polarSectorArc: Arc<any, PolarSectorGeometry> | undefined
 
-/** Resolves one D3 sector and samples its painted interaction boundary. */
-export function resolvePolarSector(
-  sector: PolarSectorGeometry,
-): ResolvedPolarSector | undefined {
+export function projectPolarSector(sector: PolarSectorGeometry) {
   if (
     !isFiniteNumber(sector.startAngle) ||
     !isFiniteNumber(sector.endAngle) ||
@@ -32,17 +29,22 @@ export function resolvePolarSector(
   ) {
     return undefined
   }
-  const generator = (polarSectorArc ??= createArc<PolarSectorGeometry>()
-    .startAngle((value) => value.startAngle)
-    .endAngle((value) => value.endAngle)
-    .innerRadius((value) => value.innerRadius)
-    .outerRadius((value) => value.outerRadius)
-    .cornerRadius((value) => value.cornerRadius))
-  const path = generator(sector)
-  if (typeof path !== 'string' || !path) return undefined
+  const generator = (polarSectorArc ??=
+    createArc<PolarSectorGeometry>().cornerRadius(
+      (value) => value.cornerRadius,
+    ))
+  return generator(sector) || undefined
+}
+
+/** Resolves one D3 sector and samples its painted interaction boundary. */
+export function resolvePolarSector(
+  sector: PolarSectorGeometry,
+): ResolvedPolarSector | undefined {
+  const path = projectPolarSector(sector)
+  if (!path) return undefined
   return {
     path,
-    points: tracePolarArcBoundary(generator, sector, 0, [sector]),
+    points: tracePolarArcBoundary(polarSectorArc!, sector, 0, [sector]),
   }
 }