Brachistochrone

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;
using cAlgo.Indicators;

namespace cAlgo
{
    [Indicator(IsOverlay = true, AutoRescale = false, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class Brachistochrone : Indicator
    {
        [Parameter("Magic Number", DefaultValue = 0)]
        public int mgc { get; set; }
        [Parameter("Icon Color", DefaultValue = "Blue")]
        public string col { get; set; }
        [Parameter("Icon")]
        public ChartIconType icon { get; set; }
        [Parameter("Show Variance", DefaultValue = true)]
        public bool variance { get; set; }
        [Parameter("Show Projection", DefaultValue = false)]
        public bool proj { get; set; }

        [Output("Main", LineColor = "White")]
        public IndicatorDataSeries Result { get; set; }
        [Output("Upper Band", LineColor = "White", LineStyle = LineStyle.DotsRare)]
        public IndicatorDataSeries up { get; set; }
        [Output("Lower Band", LineColor = "White", LineStyle = LineStyle.DotsRare)]
        public IndicatorDataSeries down { get; set; }

        private int x1;
        private int x2;
        private double y1;
        private double y2;

        private string selected = "none";
        private string name;


        protected override void Initialize()
        {
            name = " " + mgc.ToString();
            drawCursors();
            Chart.ObjectHoverChanged += OnChartObjectHoverChanged;
            Chart.MouseUp += OnChartMouseUp;
        }

        void OnChartMouseUp(ChartMouseEventArgs obj)
        {
            if (selected == "Brachi1")
            {
                x1 = (int)obj.BarIndex;
                y1 = (double)obj.YValue;
                drawBrachi();
            }
            if (selected == "Brachi2")
            {
                x2 = (int)obj.BarIndex;
                y2 = (double)obj.YValue;
                drawBrachi();
            }
        }

        void OnChartObjectHoverChanged(ChartObjectHoverChangedEventArgs obj)
        {
            if (!obj.IsObjectHovered)
                selected = "none";
            else
                try
                {
                    if (obj.ChartObject.Name == "Brachi1" + name)
                    {
                        selected = "Brachi1";
                    }
                    else if (obj.ChartObject.Name == "Brachi2" + name)
                    {
                        selected = "Brachi2";
                    }
                    else
                        selected = "none";

                } catch (Exception e)
                {
                    Print(e);
                }
        }

        private void drawCursors()
        {
            int index = Chart.FirstVisibleBarIndex + 10;
            Chart.DrawIcon("Brachi1" + name, icon, index, (Chart.TopY - Chart.BottomY) * 0.75 + Chart.BottomY, Color.FromName(col)).IsInteractive = true;
            Chart.DrawIcon("Brachi2" + name, icon, index, (Chart.TopY - Chart.BottomY) * 0.75 + Chart.BottomY, Color.FromName(col)).IsInteractive = true;
            x1 = index;
            x2 = index;
            y1 = (Chart.TopY - Chart.BottomY) * 0.75 + Chart.BottomY;
            y2 = (Chart.TopY - Chart.BottomY) * 0.75 + Chart.BottomY;
        }

        private void drawBrachi()
        {
            for (int i = 0; i < Chart.BarsTotal + 500; i++)
            {
                up[i] = double.NaN;
                down[i] = double.NaN;
                Result[i] = double.NaN;
            }
            //considerando la brachi incentrata con il punto iniziale x1 nell'origine degli assi, l è la semilunghezza della proiezione sulle ascisse, h è il diametro della circonferenza generatrice
            double l = x2 - x1;
            double h = y2 - y1;
            double k = l / (h * Math.PI / 2);
            for (int i = 0; i < (proj ? l * 2 : l); i++)
            {
                double t = bisect((k * h) / 2, 0.01, i);
                Result[x1 + i] = (h / 2) * (1 - Math.Cos(t)) + y1;
            }
            //drawing variance
            if (variance)
            {
                double sum = 0;
                for (int i = x1; i < x2; i++)
                {
                    sum += !double.IsNaN(Result[i] - MarketSeries.Close[i]) ? Math.Abs(Result[i] - MarketSeries.Close[i]) : 0;
                }
                sum /= x1 - x2;
                for (int i = x1; i < x2; i++)
                {
                    up[i] = Result[i] + sum;
                    down[i] = Result[i] - sum;
                }
            }
        }

        private double bisect(double kh2, double precision, double result)
        {
            double a = 0;
            double b = proj ? 2 * Math.PI + 1 : Math.PI;

            double t = 0;

            if (xFunction(kh2, a, result) * xFunction(kh2, b, result) >= 0)
            {
                return 0;
            }
            while (Math.Abs(xFunction(kh2, t, result)) > precision)
            {
                double mid = (a + b) / 2;
                if (xFunction(kh2, a, result) * xFunction(kh2, mid, result) < 0)
                {
                    b = mid;
                    t = mid;
                }
                else if (xFunction(kh2, b, result) * xFunction(kh2, mid, result) < 0)
                {
                    a = mid;
                    t = mid;
                }
            }
            return t;
        }

        private double xFunction(double kh2, double t, double result)
        {
            return kh2 * (t - Math.Sin(t)) - result;
        }

        public override void Calculate(int index)
        {

        }
    }
}