The flag of Vietnam

The_flag_of_Vietnam.swift

import UIKit
import PlaygroundSupport

class StarView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .red
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func draw(_ rect: CGRect) {
        //create path
        let path = UIBezierPath()
        
        
        let xCenter: CGFloat = rect.size.width/2
        let yCenter: CGFloat = rect.size.height/2
        
        let w = CGFloat(rect.height/2)
        let r = w / 2.0
        let flip: CGFloat = -1.0
        
        let polySide = CGFloat(5)
        
        let theta = 2.0*Double.pi*Double(2.0/polySide)
        
        path.move(to: CGPoint(x: xCenter, y: r*flip+yCenter))
        
        for i in 1..<Int(polySide) {
            let x: CGFloat = r*CGFloat(sin(Double(i)*theta))
            let y: CGFloat = r*CGFloat(cos(Double(i)*theta))
            
            path.addLine(to: CGPoint(x: x+xCenter, y: y*flip+yCenter))
        }
        
        path.close()
        
        // stroke
        UIColor.yellow.set()
        path.lineWidth = 2.0
        path.stroke()
        
        // fill
        let fillColor = UIColor.yellow
        fillColor.setFill()
        path.fill()
   
    }
}


let view = StarView(frame: CGRect(x: 0, y: 0, width: 600, height: 300))

PlaygroundPage.current.liveView = view
PlaygroundPage.current.needsIndefiniteExecution = true