Shrink Geo Coordinates Evenly

GeoHelper.cs

public class GeoHelper
{
    public static List<GeoLocation> ShrinkCoordinates(
        List<GeoLocation> coordinates,
        int count,
        bool removeDuplication = true,
        bool isClosedLoop = false)
    {
        if (coordinates == null || coordinates.Count <= 1)
            return coordinates;

        const double tolerance = 0.000001;
        var points = new List<GeoLocation>();

        if (removeDuplication)
        {
            // if removeDuplication is true and if last point is same as first point, it will be removed,
            // if we want to keep the loop, need append the first later
            foreach (var coordinate in coordinates.Where(
                         coordinate =>
                             !points.Any(_ => Math.Abs(_.Longitude - coordinate.Longitude) < tolerance
                                              && Math.Abs(_.Latitude - coordinate.Latitude) < tolerance)))
                points.Add(coordinate);
        }
        else
        {
            points = coordinates;
        }

        var first = points.First();
        if (points.Count <= 2 || points.Count <= count)
        {
            // if the result is less than count, return the result
            if (isClosedLoop) points.Add(first);
            return points;
        }

        // remove the first point in order to keep the first and last
        points.RemoveAt(0);

        var result = new List<GeoLocation>();
        var remainingCount = isClosedLoop ? count - 2 : count - 1;
        for (var i = 1; i <= remainingCount; i++)
            result.Add(points[(int)Math.Round(i * ((double)points.Count / remainingCount) - 1)]);

        // append back the first
        result.Insert(0, first);

        // if it is a closed loop, append the last
        if (isClosedLoop)
            result.Add(first);

        return result;
    }
}

public class GeoLocation
{      
    public GeoLocation(double latitude, double longitude)
    {
        Latitude = latitude;
        Longitude = longitude;
    }

    public double Latitude { get; }
    public double Longitude { get; }
}