feat: element alignments - snapping (#6256)

Co-authored-by: Ryan Di <ryan.weihao.di@gmail.com>
Co-authored-by: dwelle <luzar.david@gmail.com>

src/math.ts

@@ -472,3 +472,36 @@ export const isRightAngle = (angle: number) => {
   // angle, which we can check with modulo after rounding.
   return Math.round((angle / Math.PI) * 10000) % 5000 === 0;
 };
+
+// Given two ranges, return if the two ranges overlap with each other
+// e.g. [1, 3] overlaps with [2, 4] while [1, 3] does not overlap with [4, 5]
+export const rangesOverlap = (
+  [a0, a1]: [number, number],
+  [b0, b1]: [number, number],
+) => {
+  if (a0 <= b0) {
+    return a1 >= b0;
+  }
+
+  if (a0 >= b0) {
+    return b1 >= a0;
+  }
+
+  return false;
+};
+
+// Given two ranges,return ther intersection of the two ranges if any
+// e.g. the intersection of [1, 3] and [2, 4] is [2, 3]
+export const rangeIntersection = (
+  rangeA: [number, number],
+  rangeB: [number, number],
+): [number, number] | null => {
+  const rangeStart = Math.max(rangeA[0], rangeB[0]);
+  const rangeEnd = Math.min(rangeA[1], rangeB[1]);
+
+  if (rangeStart <= rangeEnd) {
+    return [rangeStart, rangeEnd];
+  }
+
+  return null;
+};