Rotating a CALayer 90 degrees?

Obj-C:

theLayer.transform = CATransform3DMakeRotation(90.0 / 180.0 * M_PI, 0.0, 0.0, 1.0);

Swift:

theLayer.transform = CATransform3DMakeRotation(90.0 / 180.0 * .pi, 0.0, 0.0, 1.0)

That is, transform the layer such that it is rotated by 90 degrees (π / 2 radians), with 100% of that rotation taking place around the z-axis.

If I'm animating it I use something like this in my apps:

- (NSObject *) defineZRotation {    // Define rotation on z axis    float degreesVariance = 90;    // object will always take shortest path, so that    // a rotation of less than 180 deg will move clockwise, and more than will move counterclockwise    float radiansToRotate = DegreesToRadians( degreesVariance );    CATransform3D zRotation;    zRotation = CATransform3DMakeRotation(radiansToRotate, 0, 0, 1.0);      // create an animation to hold "zRotation" transform    CABasicAnimation *animateZRotation;    animateZRotation = [CABasicAnimation animationWithKeyPath:@"transform"];    // Assign "zRotation" to animation    animateZRotation.toValue = [NSValue valueWithCATransform3D:zRotation];    // Duration, repeat count, etc    animateZRotation.duration = 1.5;//change this depending on your animation needs    // Here set cumulative, repeatCount, kCAFillMode, and others found in    // the CABasicAnimation Class Reference.    return animateZRotation;}

Of course you can use it anywhere, don;t have to return it from a method if that doesn;t suit your needs.

Basically something like that:

CGAffineTransform rotateTransform = CGAffineTransformMakeRotation(M_PI / 2.0);[myCALayer setAffineTransform:rotateTransform];

EDIT: It'll rotate clockwise or counter-clockwise depending on the platform (iOS or Mac OS).