private void UpdataAABB(double elapsed) { aabb.Clear(); float x, y; for (int i = 0; i < count; i++) { x = pointmass_list[i].position.X; y = pointmass_list[i].position.Y; aabb.Add(x, y); x += (float)(pointmass_list[i].velocity.X * elapsed); y += (float)(pointmass_list[i].velocity.Y * elapsed); aabb.Add(x, y); } }