UIImageView: get transformed UIImage

Question

I\'m rotating UIImageView using this:

[UIView beginAnimations:nil context:nil];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationCurve:UI         


        

Answer 1

Here is swift 4.1 version of heximal's answer.

extension CGImage {

    func rotated(by angle: CGFloat) -> CGImage? {
        let angleInRadians = angle * .pi / 180

        let imgRect = CGRect(x: 0, y: 0, width: width, height: height)
        let transform = CGAffineTransform.identity.rotated(by: angleInRadians)
        let rotatedRect = imgRect.applying(transform)
        let colorSpace = CGColorSpaceCreateDeviceRGB()

        guard let bmContext = CGContext(
            data: nil,
            width: Int(rotatedRect.size.width),
            height: Int(rotatedRect.size.height),
            bitsPerComponent: 8,
            bytesPerRow: 0,
            space: colorSpace,
            bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue)
            else {
                return nil
        }

        bmContext.setAllowsAntialiasing(true)
        bmContext.setShouldAntialias(true)
        bmContext.interpolationQuality = .high
        bmContext.translateBy(x: rotatedRect.size.width * 0.5, y: rotatedRect.size.height * 0.5)
        bmContext.rotate(by: angleInRadians)
        let drawRect = CGRect(
            origin: CGPoint(x: -imgRect.size.width * 0.5, y: -imgRect.size.height * 0.5),
            size: imgRect.size)
        bmContext.draw(self, in: drawRect)

        guard let rotatedImage = bmContext.makeImage() else { return nil }

        return rotatedImage
    }

}