AS3里,反正切atan2函數(shù)比反正切atan函數(shù)(即角的對邊比鄰邊)更為有用,它可以讓我們做出對物體正確的旋轉(zhuǎn).請記住Flash里的y軸 坐標與數(shù)學的是顛倒的.(上面演示所示),Flash是以弧度來計算的!坐標上的刻度值位置不太準,沒校對大家就大概移到相應(yīng)的點的位置上就可以驗證下面 的列表值

atan(val:Number) atan2(y:Number,x:Number)

弧度角度換算公式:

弧度轉(zhuǎn)為角度
degree = radians * 180 / PI

角度轉(zhuǎn)為弧度
radians = degree * PI / 180

當用atan函數(shù)時(注意是近似值):[弧度/度]

Math.atan(1/2)≈0.4636476090008061≈26.56505117707799°
Math.atan(-1/2)≈-0.4636476090008061≈-26.56505117707799°
Math.atan(-1/-2)≈0.4636476090008061≈26.56505117707799°
Math.atan(1/-2)≈-0.4636476090008061≈-26.56505117707799°

當用atan2函數(shù)時(注意是近似值):[弧度/度]

Math.atan2(1,2)≈0.4636476090008061≈26.56505117707799°
Math.atan2(-1,2)≈-0.4636476090008061≈-26.56505117707799°
Math.atan2(-1,-2)≈-2.677945044588987≈-153.43494882292202°
Math.atan2(1,-2)≈2.677945044588987≈153.43494882292202°