CustomLoadingAnimation2.swift

import SwiftUI

struct LoadingView: View {
    @State var theta: Double = 0
    let radius: Double = 60

    var body: some View {
        ZStack {
            ForEach(0..<8) { index in
                let offset = ((2 * .pi) * Double(index)) / 8
                let theta = theta + offset
                Dot(radius: radius, theta: theta, offset: offset)
            }
        }
        .task {
            withAnimation(.linear(duration: 2).repeatForever(autoreverses: false)) {
                theta = 2 * .pi
            }
        }
    }
}

struct Dot: View, Animatable {
    var radius, theta, offset: Double
    var animatableData: Double { get { theta } set { theta = newValue } }

    var body: some View {
        let scale = 0.5 + (abs((theta - .pi)
            .remainder(dividingBy: 2 * .pi)))/(2 * .pi)
        let color = color(value: scale)
        Circle()
            .frame(width: 30)
            .scaleEffect(x: scale, y: scale)
            .offset(
                x: radius * (cos(theta + offset) + cos(offset)),
                y: radius * (sin(theta + offset) + sin(offset))
            )
            .foregroundStyle(color)
            .shadow(color: color.opacity(0.5), radius: 10, y: 15 * scale)
    }

    func color(value: Double) -> Color {
        Color(hue: value, saturation: 1, brightness: 1)
    }
}

#Preview {
    LoadingView()
}