/// <summary>
		/// Change Position of Rectangle
		/// </summary>
		/// <param name="r">Rectangle</param>
		/// <param name="offset">Position Offset</param>
		/// <param name="changesize">Change Size of Rectangle</param>
		/// <returns></returns>
		public static Rectangle DeltaPos(this Rectangle r, Size offset, bool changesize = false) => r.DeltaPosSize(offset, changesize ? (offset.Scale(-1)) : Size.Empty);
		/// <summary>
		/// Increase Size of Rectangle
		/// </summary>
		/// <param name="r">Rectangle</param>
		/// <param name="sz">Increase Size</param>
		/// <param name="changepos">Change Position</param>
		/// <returns></returns>
		public static Rectangle DeltaSize(this Rectangle r, Size sz, bool changepos = false) => r.DeltaPosSize(changepos ? (sz.Scale(-1)) : Size.Empty, sz);