From b72e22f6bec717960395fcfa9923721b625afb6e Mon Sep 17 00:00:00 2001
From: Christian Byrne <cbyrne@comfy.org>
Date: Wed, 10 Sep 2025 22:38:49 -0700
Subject: [PATCH] Add Centralized Vue Node Size/Pos Tracking (#5442)
MIME-Version: 1.0
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* add dom element resize observer registry for vue node components

* Update src/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking.ts

Co-authored-by: AustinMroz <austin@comfy.org>

* refactor(vue-nodes): typed TransformState InjectionKey, safer ResizeObserver sizing, centralized slot tracking, and small readability updates

* chore: make TransformState interface non-exported to satisfy knip pre-push

* Revert "chore: make TransformState interface non-exported to satisfy knip pre-push"

This reverts commit 110ecf31dac3087683d3d53e908dbef3707efa31.

* Revert "refactor(vue-nodes): typed TransformState InjectionKey, safer ResizeObserver sizing, centralized slot tracking, and small readability updates"

This reverts commit 428752619c2761a6cf10450124a634be7eae667e.

* [refactor] Improve resize tracking composable documentation and test utilities

- Rename parameters in useVueElementTracking for clarity (appIdentifier, trackingType)
- Add comprehensive docstring with examples to prevent DOM attribute confusion
- Extract mountLGraphNode test utility to eliminate repetitive mock setup
- Add technical implementation notes documenting optimization decisions

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* remove typo comment

* convert to functional bounds collection

* remove inline import

* add interfaces for bounds mutations

* remove change log

* fix bounds collection when vue nodes turned off

* fix title offset on y

* move from resize observer to selection toolbox bounds

---------

Co-authored-by: AustinMroz <austin@comfy.org>
Co-authored-by: Benjamin Lu <benjaminlu1107@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
---
 .../canvas/useSelectionToolboxPosition.ts     |  42 ++++-
 src/renderer/core/layout/store/layoutStore.ts |  26 +++
 src/renderer/core/layout/types.ts             |  10 ++
 .../vueNodes/components/LGraphNode.vue        |   4 +-
 .../composables/useVueNodeResizeTracking.ts   | 155 ++++++++++++++++++
 src/utils/mathUtil.ts                         |  50 +++++-
 .../vueNodes/components/LGraphNode.spec.ts    | 116 +++++++++++++
 tests-ui/tests/utils/mathUtil.test.ts         |  97 +++++++++++
 8 files changed, 491 insertions(+), 9 deletions(-)
 create mode 100644 src/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking.ts
 create mode 100644 tests-ui/tests/renderer/extensions/vueNodes/components/LGraphNode.spec.ts
 create mode 100644 tests-ui/tests/utils/mathUtil.test.ts

diff --git a/src/composables/canvas/useSelectionToolboxPosition.ts b/src/composables/canvas/useSelectionToolboxPosition.ts
index 8e327b05f..efb8d5ca7 100644
--- a/src/composables/canvas/useSelectionToolboxPosition.ts
+++ b/src/composables/canvas/useSelectionToolboxPosition.ts
@@ -3,8 +3,12 @@ import type { Ref } from 'vue'
 
 import { useCanvasTransformSync } from '@/composables/canvas/useCanvasTransformSync'
 import { useSelectedLiteGraphItems } from '@/composables/canvas/useSelectedLiteGraphItems'
-import { createBounds } from '@/lib/litegraph/src/litegraph'
+import { useVueFeatureFlags } from '@/composables/useVueFeatureFlags'
+import type { ReadOnlyRect } from '@/lib/litegraph/src/interfaces'
+import { LGraphNode } from '@/lib/litegraph/src/litegraph'
+import { layoutStore } from '@/renderer/core/layout/store/layoutStore'
 import { useCanvasStore } from '@/stores/graphStore'
+import { computeUnionBounds } from '@/utils/mathUtil'
 
 /**
  * Manages the position of the selection toolbox independently.
@@ -16,6 +20,7 @@ export function useSelectionToolboxPosition(
   const canvasStore = useCanvasStore()
   const lgCanvas = canvasStore.getCanvas()
   const { getSelectableItems } = useSelectedLiteGraphItems()
+  const { shouldRenderVueNodes } = useVueFeatureFlags()
 
   // World position of selection center
   const worldPosition = ref({ x: 0, y: 0 })
@@ -34,17 +39,40 @@ export function useSelectionToolboxPosition(
     }
 
     visible.value = true
-    const bounds = createBounds(selectableItems)
 
-    if (!bounds) {
-      return
+    // Get bounds for all selected items
+    const allBounds: ReadOnlyRect[] = []
+    for (const item of selectableItems) {
+      // Skip items without valid IDs
+      if (item.id == null) continue
+
+      if (shouldRenderVueNodes.value && typeof item.id === 'string') {
+        // Use layout store for Vue nodes (only works with string IDs)
+        const layout = layoutStore.getNodeLayoutRef(item.id).value
+        if (layout) {
+          allBounds.push([
+            layout.bounds.x,
+            layout.bounds.y,
+            layout.bounds.width,
+            layout.bounds.height
+          ])
+        }
+      } else {
+        // Fallback to LiteGraph bounds for regular nodes or non-string IDs
+        if (item instanceof LGraphNode) {
+          const bounds = item.getBounding()
+          allBounds.push([bounds[0], bounds[1], bounds[2], bounds[3]] as const)
+        }
+      }
     }
 
-    const [xBase, y, width] = bounds
+    // Compute union bounds
+    const unionBounds = computeUnionBounds(allBounds)
+    if (!unionBounds) return
 
     worldPosition.value = {
-      x: xBase + width / 2,
-      y: y
+      x: unionBounds.x + unionBounds.width / 2,
+      y: unionBounds.y - 10
     }
 
     updateTransform()
diff --git a/src/renderer/core/layout/store/layoutStore.ts b/src/renderer/core/layout/store/layoutStore.ts
index 10cb420eb..ca5d67120 100644
--- a/src/renderer/core/layout/store/layoutStore.ts
+++ b/src/renderer/core/layout/store/layoutStore.ts
@@ -19,6 +19,7 @@ import type {
   LayoutOperation,
   MoveNodeOperation,
   MoveRerouteOperation,
+  NodeBoundsUpdate,
   ResizeNodeOperation,
   SetNodeZIndexOperation
 } from '@/renderer/core/layout/types'
@@ -1425,6 +1426,31 @@ class LayoutStoreImpl implements LayoutStore {
   getStateAsUpdate(): Uint8Array {
     return Y.encodeStateAsUpdate(this.ydoc)
   }
+
+  /**
+   * Batch update node bounds using Yjs transaction for atomicity.
+   */
+  batchUpdateNodeBounds(updates: NodeBoundsUpdate[]): void {
+    if (updates.length === 0) return
+
+    // Set source to Vue for these DOM-driven updates
+    const originalSource = this.currentSource
+    this.currentSource = LayoutSource.Vue
+
+    this.ydoc.transact(() => {
+      for (const { nodeId, bounds } of updates) {
+        const ynode = this.ynodes.get(nodeId)
+        if (!ynode) continue
+
+        this.spatialIndex.update(nodeId, bounds)
+        ynode.set('bounds', bounds)
+        ynode.set('size', { width: bounds.width, height: bounds.height })
+      }
+    }, this.currentActor)
+
+    // Restore original source
+    this.currentSource = originalSource
+  }
 }
 
 // Create singleton instance
diff --git a/src/renderer/core/layout/types.ts b/src/renderer/core/layout/types.ts
index fdfcff430..1dbd936d9 100644
--- a/src/renderer/core/layout/types.ts
+++ b/src/renderer/core/layout/types.ts
@@ -31,6 +31,11 @@ export interface Bounds {
   height: number
 }
 
+export interface NodeBoundsUpdate {
+  nodeId: NodeId
+  bounds: Bounds
+}
+
 export type NodeId = string
 export type LinkId = number
 export type RerouteId = number
@@ -320,4 +325,9 @@ export interface LayoutStore {
   setActor(actor: string): void
   getCurrentSource(): LayoutSource
   getCurrentActor(): string
+
+  // Batch updates
+  batchUpdateNodeBounds(
+    updates: Array<{ nodeId: NodeId; bounds: Bounds }>
+  ): void
 }
diff --git a/src/renderer/extensions/vueNodes/components/LGraphNode.vue b/src/renderer/extensions/vueNodes/components/LGraphNode.vue
index a880b34d0..b01300fd3 100644
--- a/src/renderer/extensions/vueNodes/components/LGraphNode.vue
+++ b/src/renderer/extensions/vueNodes/components/LGraphNode.vue
@@ -113,7 +113,6 @@
 <script setup lang="ts">
 import { computed, inject, onErrorCaptured, ref, toRef, watch } from 'vue'
 
-// Import the VueNodeData type
 import type { VueNodeData } from '@/composables/graph/useGraphNodeManager'
 import { useErrorHandling } from '@/composables/useErrorHandling'
 import { LiteGraph } from '@/lib/litegraph/src/litegraph'
@@ -122,6 +121,7 @@ import { useNodeLayout } from '@/renderer/extensions/vueNodes/layout/useNodeLayo
 import { LODLevel, useLOD } from '@/renderer/extensions/vueNodes/lod/useLOD'
 import { cn } from '@/utils/tailwindUtil'
 
+import { useVueElementTracking } from '../composables/useVueNodeResizeTracking'
 import NodeContent from './NodeContent.vue'
 import NodeHeader from './NodeHeader.vue'
 import NodeSlots from './NodeSlots.vue'
@@ -154,6 +154,8 @@ const emit = defineEmits<{
   'update:title': [nodeId: string, newTitle: string]
 }>()
 
+useVueElementTracking(props.nodeData.id, 'node')
+
 // Inject selection state from parent
 const selectedNodeIds = inject(SelectedNodeIdsKey)
 if (!selectedNodeIds) {
diff --git a/src/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking.ts b/src/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking.ts
new file mode 100644
index 000000000..c6be50285
--- /dev/null
+++ b/src/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking.ts
@@ -0,0 +1,155 @@
+/**
+ * Generic Vue Element Tracking System
+ *
+ * Automatically tracks DOM size and position changes for Vue-rendered elements
+ * and syncs them to the layout store. Uses a single shared ResizeObserver for
+ * performance, with elements identified by configurable data attributes.
+ *
+ * Supports different element types (nodes, slots, widgets, etc.) with
+ * customizable data attributes and update handlers.
+ */
+import { getCurrentInstance, onMounted, onUnmounted } from 'vue'
+
+import { layoutStore } from '@/renderer/core/layout/store/layoutStore'
+import type { Bounds, NodeId } from '@/renderer/core/layout/types'
+
+/**
+ * Generic update item for element bounds tracking
+ */
+interface ElementBoundsUpdate {
+  /** Element identifier (could be nodeId, widgetId, slotId, etc.) */
+  id: string
+  /** Updated bounds */
+  bounds: Bounds
+}
+
+/**
+ * Configuration for different types of tracked elements
+ */
+interface ElementTrackingConfig {
+  /** Data attribute name (e.g., 'nodeId') */
+  dataAttribute: string
+  /** Handler for processing bounds updates */
+  updateHandler: (updates: ElementBoundsUpdate[]) => void
+}
+
+/**
+ * Registry of tracking configurations by element type
+ */
+const trackingConfigs: Map<string, ElementTrackingConfig> = new Map([
+  [
+    'node',
+    {
+      dataAttribute: 'nodeId',
+      updateHandler: (updates) => {
+        const nodeUpdates = updates.map(({ id, bounds }) => ({
+          nodeId: id as NodeId,
+          bounds
+        }))
+        layoutStore.batchUpdateNodeBounds(nodeUpdates)
+      }
+    }
+  ]
+])
+
+// Single ResizeObserver instance for all Vue elements
+const resizeObserver = new ResizeObserver((entries) => {
+  // Group updates by element type
+  const updatesByType = new Map<string, ElementBoundsUpdate[]>()
+
+  for (const entry of entries) {
+    if (!(entry.target instanceof HTMLElement)) continue
+    const element = entry.target
+
+    // Find which type this element belongs to
+    let elementType: string | undefined
+    let elementId: string | undefined
+
+    for (const [type, config] of trackingConfigs) {
+      const id = element.dataset[config.dataAttribute]
+      if (id) {
+        elementType = type
+        elementId = id
+        break
+      }
+    }
+
+    if (!elementType || !elementId) continue
+
+    const { inlineSize: width, blockSize: height } = entry.contentBoxSize[0]
+    const rect = element.getBoundingClientRect()
+
+    const bounds: Bounds = {
+      x: rect.left,
+      y: rect.top,
+      width,
+      height: height
+    }
+
+    if (!updatesByType.has(elementType)) {
+      updatesByType.set(elementType, [])
+    }
+    const updates = updatesByType.get(elementType)
+    if (updates) {
+      updates.push({ id: elementId, bounds })
+    }
+  }
+
+  // Process updates by type
+  for (const [type, updates] of updatesByType) {
+    const config = trackingConfigs.get(type)
+    if (config && updates.length > 0) {
+      config.updateHandler(updates)
+    }
+  }
+})
+
+/**
+ * Tracks DOM element size/position changes for a Vue component and syncs to layout store
+ *
+ * Sets up automatic ResizeObserver tracking when the component mounts and cleans up
+ * when unmounted. The tracked element is identified by a data attribute set on the
+ * component's root DOM element.
+ *
+ * @param appIdentifier - Application-level identifier for this tracked element (not a DOM ID)
+ *                       Example: node ID like 'node-123', widget ID like 'widget-456'
+ * @param trackingType - Type of element being tracked, determines which tracking config to use
+ *                      Example: 'node' for Vue nodes, 'widget' for UI widgets
+ *
+ * @example
+ * ```ts
+ * // Track a Vue node component with ID 'my-node-123'
+ * useVueElementTracking('my-node-123', 'node')
+ *
+ * // Would set data-node-id="my-node-123" on the component's root element
+ * // and sync size changes to layoutStore.batchUpdateNodeBounds()
+ * ```
+ */
+export function useVueElementTracking(
+  appIdentifier: string,
+  trackingType: string
+) {
+  onMounted(() => {
+    const element = getCurrentInstance()?.proxy?.$el
+    if (!(element instanceof HTMLElement) || !appIdentifier) return
+
+    const config = trackingConfigs.get(trackingType)
+    if (config) {
+      // Set the appropriate data attribute
+      element.dataset[config.dataAttribute] = appIdentifier
+      resizeObserver.observe(element)
+    }
+  })
+
+  onUnmounted(() => {
+    const element = getCurrentInstance()?.proxy?.$el
+    if (!(element instanceof HTMLElement)) return
+
+    const config = trackingConfigs.get(trackingType)
+    if (config) {
+      // Remove the data attribute
+      delete element.dataset[config.dataAttribute]
+      resizeObserver.unobserve(element)
+    }
+  })
+}
diff --git a/src/utils/mathUtil.ts b/src/utils/mathUtil.ts
index 2fb74e1cf..8655451c5 100644
--- a/src/utils/mathUtil.ts
+++ b/src/utils/mathUtil.ts
@@ -1,3 +1,6 @@
+import type { ReadOnlyRect } from '@/lib/litegraph/src/interfaces'
+import type { Bounds } from '@/renderer/core/layout/types'
+
 /**
  * Finds the greatest common divisor (GCD) for two numbers.
  *
@@ -5,7 +8,7 @@
  * @param b - The second number.
  * @returns The GCD of the two numbers.
  */
-const gcd = (a: number, b: number): number => {
+export const gcd = (a: number, b: number): number => {
   return b === 0 ? a : gcd(b, a % b)
 }
 
@@ -19,3 +22,48 @@ const gcd = (a: number, b: number): number => {
 export const lcm = (a: number, b: number): number => {
   return Math.abs(a * b) / gcd(a, b)
 }
+
+/**
+ * Computes the union (bounding box) of multiple rectangles using a single-pass algorithm.
+ *
+ * Finds the minimum and maximum x/y coordinates across all rectangles to create
+ * a single bounding rectangle that contains all input rectangles. Optimized for
+ * performance with V8-friendly tuple access patterns.
+ *
+ * @param rectangles - Array of rectangle tuples in [x, y, width, height] format
+ * @returns Bounds object with union rectangle, or null if no rectangles provided
+ */
+export function computeUnionBounds(
+  rectangles: readonly ReadOnlyRect[]
+): Bounds | null {
+  const n = rectangles.length
+  if (n === 0) {
+    return null
+  }
+
+  const r0 = rectangles[0]
+  let minX = r0[0]
+  let minY = r0[1]
+  let maxX = minX + r0[2]
+  let maxY = minY + r0[3]
+
+  for (let i = 1; i < n; i++) {
+    const r = rectangles[i]
+    const x1 = r[0]
+    const y1 = r[1]
+    const x2 = x1 + r[2]
+    const y2 = y1 + r[3]
+
+    if (x1 < minX) minX = x1
+    if (y1 < minY) minY = y1
+    if (x2 > maxX) maxX = x2
+    if (y2 > maxY) maxY = y2
+  }
+
+  return {
+    x: minX,
+    y: minY,
+    width: maxX - minX,
+    height: maxY - minY
+  }
+}
diff --git a/tests-ui/tests/renderer/extensions/vueNodes/components/LGraphNode.spec.ts b/tests-ui/tests/renderer/extensions/vueNodes/components/LGraphNode.spec.ts
new file mode 100644
index 000000000..b2faf8b7a
--- /dev/null
+++ b/tests-ui/tests/renderer/extensions/vueNodes/components/LGraphNode.spec.ts
@@ -0,0 +1,116 @@
+import { mount } from '@vue/test-utils'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { ref } from 'vue'
+
+import type { VueNodeData } from '@/composables/graph/useGraphNodeManager'
+import { SelectedNodeIdsKey } from '@/renderer/core/canvas/injectionKeys'
+import LGraphNode from '@/renderer/extensions/vueNodes/components/LGraphNode.vue'
+import { useVueElementTracking } from '@/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking'
+
+vi.mock(
+  '@/renderer/extensions/vueNodes/composables/useVueNodeResizeTracking',
+  () => ({
+    useVueElementTracking: vi.fn()
+  })
+)
+
+vi.mock('@/composables/useErrorHandling', () => ({
+  useErrorHandling: () => ({
+    toastErrorHandler: vi.fn()
+  })
+}))
+
+vi.mock('@/renderer/extensions/vueNodes/layout/useNodeLayout', () => ({
+  useNodeLayout: () => ({
+    position: { x: 100, y: 50 },
+    startDrag: vi.fn(),
+    handleDrag: vi.fn(),
+    endDrag: vi.fn()
+  })
+}))
+
+vi.mock('@/renderer/extensions/vueNodes/lod/useLOD', () => ({
+  useLOD: () => ({
+    lodLevel: { value: 0 },
+    shouldRenderWidgets: { value: true },
+    shouldRenderSlots: { value: true },
+    shouldRenderContent: { value: false },
+    lodCssClass: { value: '' }
+  }),
+  LODLevel: { MINIMAL: 0 }
+}))
+
+describe('LGraphNode', () => {
+  const mockNodeData: VueNodeData = {
+    id: 'test-node-123',
+    title: 'Test Node',
+    type: 'TestNode',
+    mode: 0,
+    flags: {},
+    inputs: [],
+    outputs: [],
+    widgets: [],
+    selected: false,
+    executing: false
+  }
+
+  const mountLGraphNode = (props: any, selectedNodeIds = new Set()) => {
+    return mount(LGraphNode, {
+      props,
+      global: {
+        provide: {
+          [SelectedNodeIdsKey as symbol]: ref(selectedNodeIds)
+        }
+      }
+    })
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should call resize tracking composable with node ID', () => {
+    mountLGraphNode({ nodeData: mockNodeData })
+
+    expect(useVueElementTracking).toHaveBeenCalledWith('test-node-123', 'node')
+  })
+
+  it('should render with data-node-id attribute', () => {
+    const wrapper = mountLGraphNode({ nodeData: mockNodeData })
+
+    expect(wrapper.attributes('data-node-id')).toBe('test-node-123')
+  })
+
+  it('should render node title', () => {
+    const wrapper = mountLGraphNode({ nodeData: mockNodeData })
+
+    expect(wrapper.text()).toContain('Test Node')
+  })
+
+  it('should apply selected styling when selected prop is true', () => {
+    const wrapper = mountLGraphNode(
+      { nodeData: mockNodeData, selected: true },
+      new Set(['test-node-123'])
+    )
+
+    expect(wrapper.classes()).toContain('border-blue-500')
+    expect(wrapper.classes()).toContain('ring-2')
+    expect(wrapper.classes()).toContain('ring-blue-300')
+  })
+
+  it('should apply executing animation when executing prop is true', () => {
+    const wrapper = mountLGraphNode({ nodeData: mockNodeData, executing: true })
+
+    expect(wrapper.classes()).toContain('animate-pulse')
+  })
+
+  it('should emit node-click event on pointer down', async () => {
+    const wrapper = mountLGraphNode({ nodeData: mockNodeData })
+
+    await wrapper.trigger('pointerdown')
+
+    expect(wrapper.emitted('node-click')).toHaveLength(1)
+    expect(wrapper.emitted('node-click')?.[0]).toHaveLength(2)
+    expect(wrapper.emitted('node-click')?.[0][1]).toEqual(mockNodeData)
+  })
+})
diff --git a/tests-ui/tests/utils/mathUtil.test.ts b/tests-ui/tests/utils/mathUtil.test.ts
new file mode 100644
index 000000000..c4cb16dd8
--- /dev/null
+++ b/tests-ui/tests/utils/mathUtil.test.ts
@@ -0,0 +1,97 @@
+import { describe, expect, it } from 'vitest'
+
+import type { ReadOnlyRect } from '@/lib/litegraph/src/interfaces'
+import { computeUnionBounds, gcd, lcm } from '@/utils/mathUtil'
+
+describe('mathUtil', () => {
+  describe('gcd', () => {
+    it('should compute greatest common divisor correctly', () => {
+      expect(gcd(48, 18)).toBe(6)
+      expect(gcd(100, 25)).toBe(25)
+      expect(gcd(17, 13)).toBe(1)
+      expect(gcd(0, 5)).toBe(5)
+      expect(gcd(5, 0)).toBe(5)
+    })
+  })
+
+  describe('lcm', () => {
+    it('should compute least common multiple correctly', () => {
+      expect(lcm(4, 6)).toBe(12)
+      expect(lcm(15, 20)).toBe(60)
+      expect(lcm(7, 11)).toBe(77)
+    })
+  })
+
+  describe('computeUnionBounds', () => {
+    it('should return null for empty input', () => {
+      expect(computeUnionBounds([])).toBe(null)
+    })
+
+    // Tests for tuple format (ReadOnlyRect)
+    it('should work with ReadOnlyRect tuple format', () => {
+      const tuples: ReadOnlyRect[] = [
+        [10, 20, 30, 40] as const, // bounds: 10,20 to 40,60
+        [50, 10, 20, 30] as const // bounds: 50,10 to 70,40
+      ]
+
+      const result = computeUnionBounds(tuples)
+
+      expect(result).toEqual({
+        x: 10, // min(10, 50)
+        y: 10, // min(20, 10)
+        width: 60, // max(40, 70) - min(10, 50) = 70 - 10
+        height: 50 // max(60, 40) - min(20, 10) = 60 - 10
+      })
+    })
+
+    it('should handle single ReadOnlyRect tuple', () => {
+      const tuple: ReadOnlyRect = [10, 20, 30, 40] as const
+      const result = computeUnionBounds([tuple])
+
+      expect(result).toEqual({
+        x: 10,
+        y: 20,
+        width: 30,
+        height: 40
+      })
+    })
+
+    it('should handle tuple format with negative dimensions', () => {
+      const tuples: ReadOnlyRect[] = [
+        [100, 50, -20, -10] as const, // x+width=80, y+height=40
+        [90, 45, 15, 20] as const // x+width=105, y+height=65
+      ]
+
+      const result = computeUnionBounds(tuples)
+
+      expect(result).toEqual({
+        x: 90, // min(100, 90)
+        y: 45, // min(50, 45)
+        width: 15, // max(80, 105) - min(100, 90) = 105 - 90
+        height: 20 // max(40, 65) - min(50, 45) = 65 - 45
+      })
+    })
+
+    it('should maintain optimal performance with SoA tuples', () => {
+      // Test that array access is as expected for typical selection sizes
+      const tuples: ReadOnlyRect[] = Array.from(
+        { length: 10 },
+        (_, i) =>
+          [
+            i * 20, // x
+            i * 15, // y
+            100 + i * 5, // width
+            80 + i * 3 // height
+          ] as const
+      )
+
+      const result = computeUnionBounds(tuples)
+
+      expect(result).toBeTruthy()
+      expect(result!.x).toBe(0)
+      expect(result!.y).toBe(0)
+      expect(result!.width).toBe(325)
+      expect(result!.height).toBe(242)
+    })
+  })
+})