feat: added matrix effect

Core/ParticleEffect/MatrixEffect.swift

@@ -0,0 +1,76 @@
+//
+//  MatrixEffect.swift
+//  VEMTestProject
+//
+//  Created by kjs on 2022/02/15.
+//
+
+#if os(iOS)
+import UIKit
+
+final class MatrixEffect: ParticleEffect {
+
+    func ready(with strings: [String]) {
+        setUpCells {
+            let images = strings.map { string in
+                return cgImage(from: styledLabel(with: string))
+            }
+
+            var texts = [CAEmitterCell]()
+
+            for image in images {
+                let text = CAEmitterCell()
+                text.contents = image
+                text.lifetime = 10.0
+                text.birthRate = 4.0
+
+                text.scale = 1.0
+                text.scaleRange = 0.6
+
+                text.velocity = -200.0
+                text.velocityRange = -150.0
+                texts.append(text)
+            }
+
+            return texts
+        }
+
+        setUpLayer { layer in
+            layer.emitterPosition = CGPoint(x: background.bounds.width / 2.0, y: -100)
+            layer.emitterSize = CGSize(width: background.bounds.width, height: 0)
+            layer.emitterShape = .line
+            layer.beginTime = CACurrentMediaTime()
+        }
+    }
+
+    private func styledLabel(with string: String) -> UILabel {
+        let breadthBasis = 30.0
+        let label = UILabel(frame: .init(
+            x: .zero,
+            y: .zero,
+            width: breadthBasis,
+            height: CGFloat(string.count) * breadthBasis
+        ))
+
+        label.alpha = 0.85
+        label.textColor = .green
+        label.numberOfLines = .zero
+        label.adjustsFontSizeToFitWidth = true
+        label.font = .preferredFont(forTextStyle: .body)
+        label.text = string.map{ $0.description }.joined(separator: "\n")
+
+        return label
+    }
+
+    private func cgImage(from label: UILabel) -> CGImage? {
+        UIGraphicsBeginImageContext(label.frame.size)
+        var cgImage: CGImage?
+        if let context = UIGraphicsGetCurrentContext() {
+            label.layer.render(in: context)
+            cgImage = context.makeImage()
+            UIGraphicsEndImageContext()
+        }
+        return cgImage
+    }
+}
+#endif

Core/ParticleEffect/Particle.swift

@@ -13,6 +13,7 @@ public enum Particle {
     case withSnow
     case withBubble
     case withBallon
+    case withMatrix(text: [String])
 
     public func ready(for view: UIView) -> Runable {
         switch self {
@@ -22,6 +23,10 @@ public enum Particle {
             return BubbleEffect(for: view)
         case .withBallon:
             return BalloonEffect(for: view)
+        case .withMatrix(let strings):
+            let matrixEffect = MatrixEffect(for: view)
+            matrixEffect.ready(with: strings)
+            return matrixEffect
         }
     }
 }