Proper implementation of a dial should allow linear input in two dimensions: clicking on the dial and moving up or right should increase the value of the dial, and moving down or left should decrease the value.

• 恰当设计的刻度盘应当允许在两个维度上进行线性输入，单击刻度盘并向上或者向右，就会增加刻度盘上的数值；向下或者向左就会减少数值。