ios – 关于CGAffineTransformMakeRotation旋转方向？

The angle,in radians,by which this matrix rotates the coordinate system axes. In iOS,a positive value specifies counterclockwise rotation and a negative value specifies clockwise rotation. In OS X,a positive value specifies clockwise rotation and a negative value specifies counterclockwise rotation.

所以,我通过参数90度,它应该逆时针旋转.
self.myView是灰色背景颜色视图,红色正方形视图仅用于查看旋转方向

#define degrees_TO_radians(x) (x * M_PI/180.0)
CGAffineTransform rotation = CGAffineTransformMakeRotation( degrees_TO_radians(90) );
[self.myView setTransform:rotation];

但为什么顺时针旋转？
我正在尝试使用模拟器和设备都有相同的结果,顺时针旋转
然后跟踪使用动画：

#define degrees_TO_radians(x) (x * M_PI/180.0)
CGAffineTransform rotation = CGAffineTransformMakeRotation( degrees_TO_radians(90) );
[UIView animateWithDuration:0.5
                 animations:^{
                     self.myView.transform = rotation;
                 }
                 completion:^(BOOL finished) {
                     NSLog(@"%@",NsstringFromCGAffineTransform(self.myView.transform));
                 }];

它具有相同的结果,顺时针旋转.

有人可以解释为什么,谢谢你的回复.