Function cross

packages/react-aria/src/tooltip/useSafeArea.ts:129–130

(o: Point, a: Point, b: Point)

  }

  let cross = (o: Point, a: Point, b: Point) =>
    (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x);

  let lower: Point[] = [];
  for (let p of sorted) {