void Update()
{
var a = A.position.xz();
var b = B.position.xz();
DebugUtil.DrawCircle(a, R);
DebugUtil.DrawCircle(b, R);
var r = TransformRect((a + b) / 2, new float2(2 * R, math.length(b - a)), Math.Angle(b - a));
DebugUtil.Draw(r);
DebugUtil.DrawLine(C.position.xz(), D.position.xz());
E.gameObject.SetActive(Intersect(r, C.position.xz(), D.position.xz()));
// DebugUtil.DrawCircle(r.A, .5f);
// DebugUtil.DrawCircle(r.B, .5f, Color.yellow);
// DebugUtil.DrawCircle(r.C, .5f, Color.red);
}
