Use PanGestureRecognizer translationInView to track touch location

How would i use a PanGestureRecognizer's translationInView which returns a CGPoint, to track the user touch location so that i can rotate an image so that the point where the user touches stays under the finger?

I can use CGAffineTransformRotate to do the rotation but it expe开发者_如何学JAVActs a rotation angle in radians. Currently i am using M_PI/20;

Thanks

add this to your code:

#define degreesToRadians(degrees) (M_PI * degrees / 180.0)
#define radiansToDegrees(radians) (radians * 180 / M_PI)

Apple provides these GLKit functions for conversion:

func GLKMathDegreesToRadians(_ degrees: Float) -> Float
func GLKMathRadiansToDegrees(_ radians: Float) -> Float