Scale for fullscreen camera on iPhone X

Question

I have implemented a custom camera in my app using UIImagePickerController. I previously made the camera full screen by applying this transformation:

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
    ipc = [[UIImagePickerController alloc] init];
    ipc.delegate = self;

    ipc.sourceType = UIImagePickerControllerSourceTypeCamera;
    ipc.showsCameraControls = NO;

    [[NSBundle mainBundle] loadNibNamed:@"SnapItCameraView" owner:self options:nil];
    self.overlayView.frame = ipc.cameraOverlayView.frame;
    ipc.cameraOverlayView = self.overlayView;
    self.overlayView = nil;

    //For iphone 5+
    //Camera is 426 * 320. Screen height is 568.  Multiply by 1.333 in 5 inch to fill vertical
    CGAffineTransform translate = CGAffineTransformMakeTranslation(0.0, 71.0); //This slots the preview exactly in the middle of the screen by moving it down 71 points
    ipc.cameraViewTransform = translate;

    CGAffineTransform scale = CGAffineTransformScale(translate, 1.333333, 1.333333);
    ipc.cameraViewTransform = scale;
    ipc.showsCameraControls = NO;
    ipc.tabBarController.tabBar.hidden = YES;
    ipc.allowsEditing = NO;
    [self presentViewController:ipc animated:YES completion:nil];
}

However, the camera does not fill the screen of the iPhone X. Its flush with the top of the screen, but there is a black bar at the bottom.

I assume the issue is that 1.3 is the wrong scale to vertically fill the screen. I would like the camera to fill the entire screen of the phone for the iPhone X.

Other @Matt: "I assume the issue is that 1.3 is the wrong scale to vertically fill the screen" That sounds reasonable. Can you clarify what the question is? You're not showing enough code to allow reproduction of the problem, and it isn't even clear what you think you're trying to do. — matt, Dec 14 '17 at 19:10
Yes! — I don't have an iPhone X so I can't test. But let me ask you this: if you change the hard-coded number to something else (larger?), is it better? — matt, Dec 14 '17 at 19:26

score 1 · Accepted Answer · answered Dec 14 '17 at 19:10

Hard-coding that ratio doesn't make much sense here if you can calculate it instead.

You calculated 1.3333 by dividing screen height (568) by the height of the camera view (426). That logic should work the same on the X but you need to provide the correct parameters instead of assuming all phones share the same screen dimensions.

Also keep in mind that transforming this image may result in parts of it being cut off if you chose to scale proportionately.

Scale for fullscreen camera on iPhone X

1 Answers1