A rectangle specified in terms of its top-left corner and the co-ordinate below and to the right of its bottom-right corner.
A rectangle specified in terms of its top-left corner and the co-ordinate below and to the right of its bottom-right corner.
矩形：一个矩形区域特指以其左上角为基准，沿坐标向右下方向到其右下角的范围。