import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
createParticles()
}
func createParticles() {
let v = UIView(frame: CGRect(x: 180, y: 220, width: 60, height: 60))
//v.backgroundColor = .lightGray
view.addSubview(v)
let particleEmitter = CAEmitterLayer()
particleEmitter.emitterPosition = CGPoint(x: 30, y: 30)
particleEmitter.emitterShape = kCAEmitterLayerSphere
particleEmitter.emitterSize = CGSize(width: 1, 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]
v.layer.addSublayer(particleEmitter)
UIView.animate(withDuration: 2.0, animations: {
v.alpha = 0
}) { (_) in
v.layer.sublayers?.removeAll()
}
}
func makeEmitterCell(color: UIColor) -> CAEmitterCell {
let cell = CAEmitterCell()
cell.birthRate = 2.5
cell.lifetime = 1.9
cell.lifetimeRange = 1
cell.color = color.cgColor
cell.velocity = 158
cell.velocityRange = 45
cell.emissionLongitude = CGFloat.pi
cell.emissionRange = CGFloat.pi
cell.spin = 4
cell.spinRange = 6
cell.scaleRange = 0.04
cell.scaleSpeed = 0.3
cell.xAcceleration = -0.03
cell.yAcceleration = -0.05
cell.zAcceleration = 0.2
cell.contents = UIImage(named: "cp")?.cgImage
return cell
}
}
