Source code for CodeSlicing episode on Animated Pac-Man (requires PureSwiftUI v2.1.0+)

AnimatedPacManDemo.swift

//
//  AnimatedPacManDemo.swift
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
//  of the Software, and to permit persons to whom the Software is furnished to do so,
//  subject to the following conditions:
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
//  INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
//  PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
//  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
//  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
//  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//  Created by Adam Fordyce on 23/04/2021.
//  Copyright © 2020 Adam Fordyce. All rights reserved.
//

import SwiftUI
import PureSwiftUI

private let pacManSize: CGFloat = 100
private let maxXOffset = UIScreen.halfMainWidth + pacManSize * 0.5

struct AnimatedPacManDemo: View {
    
    @State private var animatingMouth = false
    @State private var animatingPosition = false
    
    var body: some View {
        let xOffset = maxXOffset * (animatingPosition ? 1 : -1)
        PacMan(animatingMouth: animatingMouth)
            .eoFill(Color.yellow)
            .frame(pacManSize)
            .xOffset(xOffset)
            .onAppear {
                withAnimation(Animation.easeInOut(duration: 0.2).repeatForever()) {
                    animatingMouth = true
                }
                withAnimation(Animation.linear(duration: 3).repeatForever(autoreverses: false)) {
                    animatingPosition = true
                }
            }
    }
}

private struct PacMan: Shape {

    var animatableData: CGFloat
    
    init(animatingMouth: Bool) {
        animatableData = animatingMouth ? 1 : 0
    }
    
    func path(in rect: CGRect) -> Path {
        var path = Path()
        
        path.move(rect.center)
        
        //mouth
        path.arc(rect.center, radius: rect.halfHeight,
                 startAngle: 135.degrees.to(90.degrees, animatableData),
                 endAngle: 45.degrees.to(89.999.degrees, animatableData))

        //eye
        path.circle(rect[0.65, 0.2], radius: rect.widthScaled(0.05))
        
        return path
    }
}

struct AnimatedPacManDemo_Previews: PreviewProvider {
    struct AnimatedPacManDemo_Harness: View {

        var body: some View {
            AnimatedPacManDemo()
                .greedyFrame()
                .foregroundColor(.white)
                .backgroundColor(.white(0.1))
                .ignoresSafeArea()
        }
    }

    static var previews: some View {
        AnimatedPacManDemo_Harness()
            .previewDevice(.iPhone_12_Pro_Max)
    }
}