Drawing an arrow for SwiftUI

Arrow.swift

//
//  Arrow.swift
//
//  Created by Ken Itakura on 2024/02/29.
//

import SwiftUI

struct Arrow: View {
    var start: CGPoint
    var end: CGPoint
    var color: Color? = Color.black
    var tipColor: Color? // arrow tip not filled, if nil
    var lineWidth: CGFloat = 2.0
    var tipHeight: CGFloat = 20.0
    var tipWidth: CGFloat = 20.0
    
    var body: some View{
        let s = (x: Double(start.x), y: Double(start.y))
        let e = (x: Double(end.x), y: Double(end.y))
        let th = Double(tipHeight)
        let tw = Double(tipWidth)
        let vlen = sqrt(pow(e.x - s.x, 2) + pow(e.y - s.y, 2))
        let eShorten = (x: e.x - lineWidth * (e.x - s.x) / vlen,
                        y: e.y - lineWidth * (e.y - s.y) / vlen)
        let tipBase = (x: e.x - th * (e.x - s.x) / vlen,
                       y: e.y - th * (e.y - s.y) / vlen)
        let vTip = (x: (s.y - e.y)/vlen, y: (e.x - s.x)/vlen)
        let tip1vert = (x: tipBase.x + tw * vTip.x, y: tipBase.y + tw * vTip.y)
        let tip2vert = (x: tipBase.x - tw * vTip.x, y: tipBase.y - tw * vTip.y)
        
        ZStack{
            Path{ path in
                path.move(to: CGPoint(x: CGFloat(s.x), y: CGFloat(s.y)))
                if(tipColor == nil)
                {
                    path.addLine(to: CGPoint(x: CGFloat(e.x), y: CGFloat(e.y)))
                }
                else{
                    // Prevents the end of the line from protruding from the tip
                    path.addLine(to: CGPoint(x: CGFloat(eShorten.x), y: CGFloat(eShorten.y)))
                }
            }
            .stroke(color!, lineWidth: lineWidth)
            if let tipColor = tipColor{
                Path { path in
                    path.move(to: CGPoint(x: CGFloat(e.x), y: CGFloat(e.y)))
                    path.addLine(to: CGPoint(x: CGFloat(tip1vert.x), y: CGFloat(tip1vert.y)))
                    path.addLine(to: CGPoint(x: CGFloat(tip2vert.x), y: CGFloat(tip2vert.y)))
                    path.closeSubpath()
                }.fill(tipColor)
                
            }
            else{
                Path { path in
                    path.move(to: CGPoint(x: CGFloat(e.x), y: CGFloat(e.y)))
                    path.addLine(to: CGPoint(x: CGFloat(tip1vert.x), y: CGFloat(tip1vert.y)))
                    path.move(to: CGPoint(x: CGFloat(e.x), y: CGFloat(e.y)))
                    path.addLine(to: CGPoint(x: CGFloat(tip2vert.x), y: CGFloat(tip2vert.y)))
                }
                .stroke(color!, lineWidth: lineWidth)
            }
        }
    }
}

struct Arrow_Previews: PreviewProvider {
    static var previews: some View {
        let colors = [Color.red, Color.blue, Color.green, Color.yellow]
        ForEach(0..<5) { index in
            Arrow(
                start: CGPoint(x: Double.random(in: 50...200), y: Double.random(in: 50...200)),
                end: CGPoint(x: Double.random(in: 50...200), y: Double.random(in: 50...200)),
                color: colors.randomElement(),
                tipColor: colors.randomElement(),
                lineWidth: Double.random(in: 1...5),
                tipHeight: Double.random(in: 10...30),
                tipWidth:  Double.random(in: 10...30)
            )
        }
    }
}