add dom element resize observer registry for vue node components

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.
  *
@@ -5,12 +8,12 @@
  * @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)
 }
 
 /**
- * Finds the least common multiple (LCM) for two numbers.
+ * Finds the export least common multiple (LCM) for two numbers.
  *
  * @param a - The first number.
  * @param b - The second number.
@@ -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
+  }
+}