rotating layer 90° when orientation changes 180° confuses me

[coding]

Hello dev colleagues,

I seem to be a little braindead at the moment. My problem is I don't understand a specific orientation change / view rotation situation.

Based on a view that has a layer (AVCaptureVideoPreviewLayer) to preview video from camera on the iPhone's screen, I want to support landscape orientation in addition to portrait orientation (standard is portrait though). So when I rotate the device from portrait to landscape, I modify the view's frame and perform a CATransform3DMakeRotation (90 degrees = 90/180*M_PI) on the preview layer. This is working well, the following procedure confuses me though:

Changing the orientation from landscape-left to landscape-right is a rotation by 180 degree, though the view controllers message willRotateToInferfaceOrientation gets called once where i rotate the preview layer by 90 degrees. In fact, the preview layer gets rotated by 180 degrees and adapts properly to the new orientation. But I only rotate by 90 degrees in code??

Anyone who can give me a hint on this?? Thanks in advance

[smithdale87]

Can you post your rotation code?

[coding]

thanks for your interest. I definitely know that when rotating from landscape-left to landscape-right the message below (in the code) gets called once containing the desired orientation.

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
CGFloat rotationAngle = 0.0;
        if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft) { // home button is on the left side
            rotationAngle = 90.0/180.0*M_PI; // rotate left
        } else if (toInterfaceOrientation == UIInterfaceOrientationLandscapeRight) { // home button is on the right side
            rotationAngle = -90.0/180.0*M_PI; // rotate right
        }
        CATransform3D transform = CATransform3DMakeRotation(rotationAngle, 0, 0, 1.0);
        [layer setTransform:transform];
}