Page History

    func scale(velocity: CGFloat) {
        guard let device = self.device else { return }
        
        let maxZoomFactor = device.activeFormat.videoMaxZoomFactor
        let pinchVelocityDividerFactor: CGFloat = 15
        
        
        do {
            try device.lockForConfiguration()
            defer { device.unlockForConfiguration() }

            let desiredZoomFactor = device.videoZoomFactor + atan2(velocity, pinchVelocityDividerFactor)
            device.videoZoomFactor = max(1.0, min(desiredZoomFactor, maxZoomFactor))
        } catch {
            print(error)
        }
    }

        let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)
        ...
        if (overlayImage != nil) {
            let inputImage = CIImage.init(cvImageBuffer: pixelBuffer!);
            let combinedFilter = CIFilter(name: "CISourceOverCompositing")!
            combinedFilter.setValue(inputImage, forKey: "inputBackgroundImage")
            combinedFilter.setValue(overlayImage, forKey: "inputImage")

            let outputImage = combinedFilter.outputImage!
            let tmpcontext = CIContext(options: nil)
            tmpcontext.render(outputImage, to: pixelBuffer!, bounds: outputImage.extent, colorSpace: CGColorSpaceCreateDeviceRGB())

        }