Rowen

Rowen.swift

import UIKit

class ViewController: UIViewController {
  
  var emitTimer: Timer?
  var lastTouchPoints = [UITouch: CGPoint]()
  
  var symbolLayers = [CAShapeLayer]()
  let neonColors: [UIColor] = [
    UIColor(red: 1.00, green: 0.30, blue: 0.69, alpha: 1.00), // neon pink
    UIColor(red: 0.75, green: 1.00, blue: 0.00, alpha: 1.00), // neon green
    UIColor(red: 1.00, green: 0.82, blue: 0.20, alpha: 1.00), // neon yellow
    UIColor(red: 0.00, green: 0.83, blue: 1.00, alpha: 1.00), // neon blue
    UIColor(red: 1.00, green: 0.55, blue: 0.00, alpha: 1.00), // neon orange
    UIColor(red: 0.89, green: 0.00, blue: 1.00, alpha: 1.00)  // neon purple
  ]
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    view.isMultipleTouchEnabled = true
    
    // Other setup code...
  }
  
  func emitImages(forTouches touches: Set<UITouch>) {
    for touch in touches {
      let touchPoint = touch.location(in: view)
      let color = neonColors.randomElement()!
      
      let symbolLayer = CAShapeLayer()
      symbolLayer.path = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 20, height: 20)).cgPath
      symbolLayer.fillColor = color.cgColor
      symbolLayer.frame = CGRect(x: 0, y: 0, width: 20, height: 20)
      symbolLayer.position = touchPoint
      symbolLayer.opacity = 1
      symbolLayers.append(symbolLayer)
      view.layer.addSublayer(symbolLayer)
      
      let animation = CABasicAnimation(keyPath: "position")
      animation.fromValue = NSValue(cgPoint: touchPoint)
      animation.toValue = NSValue(cgPoint: randomPointAwayFromTouchPoint(touchPoint))
      animation.duration = 1
      animation.timingFunction = CAMediaTimingFunction(name: .easeOut)
      animation.fillMode = .forwards
      animation.isRemovedOnCompletion = false
      symbolLayer.add(animation, forKey: "position")
      
      let fadeOutAnimation = CABasicAnimation(keyPath: "opacity")
      fadeOutAnimation.fromValue = 1
      fadeOutAnimation.toValue = 0
      fadeOutAnimation.duration = 0.5
      fadeOutAnimation.beginTime = CACurrentMediaTime() + 0.5
      fadeOutAnimation.fillMode = .forwards
      fadeOutAnimation.isRemovedOnCompletion = false
      symbolLayer.add(fadeOutAnimation, forKey: "opacity")
      
      DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
        symbolLayer.removeFromSuperlayer()
        if let index = self.symbolLayers.firstIndex(of: symbolLayer) {
          self.symbolLayers.remove(at: index)
        }
      }
      
      // Check if touch is still in progress, and if so, emit more images in random directions
      if touch.phase != .ended && touch.phase != .cancelled {
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
          if touch.phase != .ended && touch.phase != .cancelled {
            self.emitImages(forTouches: Set([touch]))
          }
        }
      }
    }
  }
  
  
  var isTouchesMoving: Bool = false
  
  func randomPointAwayFromTouchPoint(_ touchPoint: CGPoint) -> CGPoint {
    let x = CGFloat.random(in: touchPoint.x - 100 ... touchPoint.x + 100)
    let y = CGFloat.random(in: touchPoint.y - 100 ... touchPoint.y + 100)
    return CGPoint(x: x, y: y)
  }
  
  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    isTouchesMoving = false
    emitImages(forTouches: touches)
  }
  
  override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    isTouchesMoving = true
    emitImages(forTouches: touches)
  }
  
  override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
    isTouchesMoving = false
  }
  
  override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    isTouchesMoving = false
  }
  
}