https://i.imgur.com/NgxEqfM.png
上面JS 下面Unity內建的數學函式庫 兩邊分開做類似FrameSync的同步計算
https://i.imgur.com/PWdeIbS.png
得到了不同結果 操他媽RoundToInt一定有加料 不是普通的四捨五入
結果去查Documents
If the number ends in .5 so it is halfway between two integers,
one of which is even and the other odd, the even number is returned.
為什麼要這麼做 誰看函式名稱能想到會優先回傳偶數啦幹