use submodule

excalidraw/packages/math/src/rectangle.ts

@@ -0,0 +1,39 @@
+import { pointFrom } from "./point";
+import { lineSegment, lineSegmentIntersectionPoints } from "./segment";
+
+import type { GlobalPoint, LineSegment, LocalPoint, Rectangle } from "./types";
+
+export function rectangle<P extends GlobalPoint | LocalPoint>(
+  topLeft: P,
+  bottomRight: P,
+): Rectangle<P> {
+  return [topLeft, bottomRight] as Rectangle<P>;
+}
+
+export function rectangleFromNumberSequence<
+  Point extends LocalPoint | GlobalPoint,
+>(minX: number, minY: number, maxX: number, maxY: number) {
+  return rectangle(pointFrom<Point>(minX, minY), pointFrom<Point>(maxX, maxY));
+}
+
+export function rectangleIntersectLineSegment<
+  Point extends LocalPoint | GlobalPoint,
+>(r: Rectangle<Point>, l: LineSegment<Point>): Point[] {
+  return [
+    lineSegment(r[0], pointFrom(r[1][0], r[0][1])),
+    lineSegment(pointFrom(r[1][0], r[0][1]), r[1]),
+    lineSegment(r[1], pointFrom(r[0][0], r[1][1])),
+    lineSegment(pointFrom(r[0][0], r[1][1]), r[0]),
+  ]
+    .map((s) => lineSegmentIntersectionPoints(l, s))
+    .filter((i): i is Point => !!i);
+}
+
+export function rectangleIntersectRectangle<
+  Point extends LocalPoint | GlobalPoint,
+>(rectangle1: Rectangle<Point>, rectangle2: Rectangle<Point>): boolean {
+  const [[minX1, minY1], [maxX1, maxY1]] = rectangle1;
+  const [[minX2, minY2], [maxX2, maxY2]] = rectangle2;
+
+  return minX1 < maxX2 && maxX1 > minX2 && minY1 < maxY2 && maxY1 > minY2;
+}