CALayer content goes out of bounds - iOS

Question

I am trying to implement camera zoom using CGAffinetransform. Transform is fine, but when I scale it to a bigger size, it goes out of the frame I have assigned to the AVCaptureVideoPreviewLayer. I tried setting masksToBounds property to YES but it didn't help.

Can I contain it within its frame?

Edit:
What I want is that I can specify a specific area for the camera preview layer, if I apply scaling transform to it, (i.e., frame of preview layer gets expanded), the part of the layer outside of the specified area gets clipped.

Answer 1

You should put the layer you are scaling inside of another layer and mask that one instead (the superlayer). The same thing works with views.

I.e. You have two views / layers: clippingView and scalingView where scalingView is the subview of clippingView and clippingView is the view that actually clips to it's bounds.

[clippingView addSubview:scalingView];
clippingView.clipsToBounds = YES;

or using layers

[clippingLayer addSublayer:scalingLayer];
clippingLayer.masksToBounds = YES;

Answer 2

You guys are all partially right I found but I wanted to clarify.

Lets say we added something like AVCaptureVideoPreviewLayer to the view via [self.view.layer addSublayer:previewLayer]

1. [self clipsToBounds] does NOTHING until you are telling its primary layer to mask to bounds. [self.view.layer masksToBounds];

2. Just because your view has a frame and so does its layers DOES NOT MEAN IT HAS BOUNDS. If it doesnt have bounds then there is nothing to mask to. So do this self.view.layer.bounds = self.view.frame;

So heres it all together..keep in mind I did this in my own UIView class so I dont need to call self.view.

previewLayer.bounds = self.frame;
self.layer.bounds = self.frame;

self.layer.masksToBounds = YES;
previewLayer.masksToBounds = YES;

[self setBounds:self.frame];
[self clipsToBounds];