AVCaptureDevice Camera Zoom

Question

I have a simple AVCaptureSession running to get a camera feed in my app and take photos. How can I implement the \'pinch to zoom\' functionality using a UIGestureRecognize

Answer 1

There is an easier way to handle camera zoom level with pinch recognizer. The only thing you need to do is take cameraDevice.videoZoomFactor and set it to the recognizer on .began state like this

@objc private func viewPinched(recognizer: UIPinchGestureRecognizer) {
    switch recognizer.state {
        case .began:
            recognizer.scale = cameraDevice.videoZoomFactor
        case .changed:
            let scale = recognizer.scale
            do {
                 try cameraDevice.lockForConfiguration()
                 cameraDevice.videoZoomFactor = max(cameraDevice.minAvailableVideoZoomFactor, min(scale, cameraDevice.maxAvailableVideoZoomFactor))
                 cameraDevice.unlockForConfiguration()
            }
            catch {
                print(error)
            }
        default:
            break
    }
}