Extract point to a different chart

AnimatedChart.swift

import Charts
import SwiftUI

struct Sample: Identifiable {
    var x: Double
    var y: Double

    var id: some Hashable { x }
}

struct AnimatedChart: View, Animatable {
    var animatableData: Double  = 0

    init(x: Double) {
        self.animatableData = x
    }

    var body: some View {
        Chart {
            PointMark(
                x: .value("x", animatableData),
                y: .value("y", pow(animatableData, 3))
            )
        }
        .chartLegend(.hidden)
        .chartXAxis(.hidden)
        .chartYAxis(.hidden)
    }
}

struct Samples: ChartContent {
    let samples = stride(from: -1, through: 1, by: 0.01).map {
        Sample(x: $0, y: pow($0, 3))
    }

    var body: some ChartContent {
        ForEach(samples) { sample in
            LineMark(x: .value("x", sample.x), y: .value("y", sample.y))
        }
    }
}

struct AnimatedChart_Previews: PreviewProvider {
    struct Preview: View {
        @State
        var x: Double = -1

        var body: some View {
            VStack {
                Chart {
                    Samples()
                }
                .chartOverlay(alignment: .topLeading) { chartProxy in
                    AnimatedChart(x: x)
                        .frame(
                            width: chartProxy.plotAreaSize.width,
                            height: chartProxy.plotAreaSize.height
                        )
                }
                .chartXScale(domain: -1...1)
                .chartYScale(domain: -1...1)
                .aspectRatio(1, contentMode: .fit)
                .padding()

                Spacer()
            }
            .contentShape(Rectangle())
            .onTapGesture {
                withAnimation(.linear(duration: 2)) {
                    if x > 0 {
                        x = -1
                    } else {
                        x = 1
                    }
                }
            }
        }
    }

    static var previews: some View {
        Preview()
    }
}