CAEmitterCell without contents swift code example

Example: CAEmitterCell without contents swift

func createParticles() {
    let particleEmitter = CAEmitterLayer()

    particleEmitter.emitterPosition = CGPoint(x: view.center.x, y: -96)
    particleEmitter.emitterShape = .line
    particleEmitter.emitterSize = CGSize(width: view.frame.size.width, height: 1)

    let red = makeEmitterCell(color: UIColor.red)
    let green = makeEmitterCell(color: UIColor.green)
    let blue = makeEmitterCell(color: UIColor.blue)

    particleEmitter.emitterCells = [red, green, blue]

    view.layer.addSublayer(particleEmitter)
}

func makeEmitterCell(color: UIColor) -> CAEmitterCell {
    let cell = CAEmitterCell()
    cell.birthRate = 3
    cell.lifetime = 7.0
    cell.lifetimeRange = 0
    cell.color = color.cgColor
    cell.velocity = 200
    cell.velocityRange = 50
    cell.emissionLongitude = CGFloat.pi
    cell.emissionRange = CGFloat.pi / 4
    cell.spin = 2
    cell.spinRange = 3
    cell.scaleRange = 0.5
    cell.scaleSpeed = -0.05

    cell.contents = UIImage(named: "particle_confetti")?.cgImage
    return cell
}