Returns an affine transformation matrix constructed by rotating an existing affine transform.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Graphics
An existing affine transform.
The angle, in radians, by which to rotate the affine transform. In iOS, a positive value specifies counterclockwise rotation and a negative value specifies clockwise rotation. In macOS, a positive value specifies clockwise rotation and a negative value specifies counterclockwise rotation.
A new affine transformation matrix.
You use this function to create a new affine transformation matrix by adding a rotation value to an existing affine transform. The resulting structure represents a new affine transform, which you can use (and reuse, if you want) to rotate a coordinate system.
The actual direction of rotation is dependent on the coordinate system orientation of the target platform, which is different in iOS and macOS.