func genImage() {
let width = 810
let height = 1080
let imgBytes: UnsafeMutableRawPointer = malloc(Int(width * height * 4))
let colourSpace = CGColorSpaceCreateDeviceRGB()
guard let context = CGContext(data: imgBytes, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: Int(width * 4), space: colourSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else {
free(imgBytes)
return
}
let caLayer = CALayer()
caLayer.backgroundColor = .init(red: 1.0, green: 0.9, blue: 0.5, alpha: 1.0)
caLayer.frame = CGRect(x: 0, y: 0, width: width, height: height)
// caLayer.setNeedsDisplay()
caLayer.draw(in: context)
let data3 = NSData(bytes: imgBytes, length: Int(width * height * 4))
let outputImage = UIImage(data: data3 as Data)
free(imgBytes)
}