CAEmitterLayer.swift

extension CAEmitterLayer {
    convenience init(image: CGImage) {
        self.init()
        let cell: CAEmitterCell = {
            let cell = CAEmitterCell()
            cell.birthRate = 40
            cell.contents = image
            cell.emissionLongitude = .pi / 2.0
            cell.emissionRange = CGFloat.pi / 4.0
            cell.lifetime = 16
            cell.scale = 0.3
            cell.scaleRange = 0.2
            cell.velocity = 80
            return cell
        }()
        emitterCells = [cell]
    }
}