角度轉弧度&根據弧度計算圓周上點的坐標的方法

 

角度轉弧度：  

#define AngleToRadian(angle) (M_PI/180.0f)*angle

 

以正東面為0度起點計算指定角度所對應的圓周上的點的坐標：

    float radian = AngleToRadian(angle);

    float x = center.x + cos(radian)*currentAdius;

    float y = center.y + sin(radian)*currentAdius;

　 CGPoint point = CGPointMake(x, y);

以正北面為0度起點計算指定角度所對應的圓周上的點的坐標：

    float radian = AngleToRadian(angle); 

    float x = center.x + sinf(radian)*currentAdius;

    float y = center.y - cosf(radian)*currentAdius;    

    CGPoint point = CGPointMake(x, y);