Concave body algorithm from pseudocode to C #

I am trying to convert the algorithm described here (page 12) from pseudocode to working C # code. The algorithm describes how a convex hull "transforms" into a concave hull by breaking edges that are considered too long into smaller edges. I understand the general idea the authors are suggesting, but I can't manage to convert it to working code. See below the code I got so far, including the comments (//) at the beginning of each line of pseudocode. The problem I'm running into is not so much a specific string, but I'm pretty sure the current way of calculating localMaximumDistance is wrong. If anyone has any guidance on how to approach this, I'd really love to hear them. (In pseudocode, this is the line that says "calculate the local maximum distance d for edges")

Thanks in advance for your time and feedback! :)

List<Line> concaveLineList = new List<Line>();
List<Line> sortedList = lineList.OrderByDescending(CalculateLength).ToList();
const int concaveTreshhold = 40;

PointCollection concavePointCollection = new PointCollection();
while (sortedList.Count > 0) {
    Console.WriteLine(concaveLineList.Count.ToString());
    //select the longest edge e from list A
    Line longestLine = sortedList[0];
    //remove edge e from list A
    sortedList.RemoveAt(0);
    //calculate local maximum distance d for edges - ???
    //double localMaximumDistance = CalculateLength(longestLine);
    List<Point<double>> nearbyPoints = new List<Point<double>>();

    foreach (BallUc ballUc in ballUcList) {
        if (Math.Abs(ballUc .CurrentPosition.X - longestLine.X1) > concaveTreshhold &&
        Math.Abs(ballUc .CurrentPosition.Y - longestLine.Y1) > concaveTreshhold) { 
            nearbyPoints.Add(new Point<double>(ballUc.CurrentPosition.X, ballUc.CurrentPosition.Y));
            }
        }

        double lineLenght = CalculateLength(longestLine);
        double localMaximumDistance = lineLenght / nearbyPoints.Count + concaveTreshhold * 4; //this value is based on nothing currently..

        if (lineLenght > localMaximumDistance) {
            //find the point p with the smallest maximum angle a
            Point smallestAnglePoint = new Point();
            double? smallestAngle = null;
            foreach (Point p in pointCollection) {
                if ((p.X == longestLine.X1 && p.Y == longestLine.Y1) ||
                (p.X == longestLine.X2 && p.Y == longestLine.Y2)) {
                    //these are the points already in the line.
                }
                else {
                    Line tempLine1 = new Line {X1 = p.X, X2 = longestLine.X1, Y1 = p.Y, Y2 = longestLine.Y1};
                    Line tempLine2 = new Line {X1 = p.X, X2 = longestLine.X2, Y1 = p.Y, Y2 = longestLine.Y2};

                    //calculate angle between the longest edge and the new edges
                    double angleInRadians1 = Math.Atan2(p.Y, p.X) - Math.Atan2(tempLine1.Y2, tempLine1.X2);
                    double angleInRadians2 = Math.Atan2(p.Y, p.X) - Math.Atan2(tempLine2.Y2, tempLine2.X2);
                    //select the largest angle of the two angles
                    double largestLocalAngle = Math.Max(angleInRadians1, angleInRadians2);

                    //in case of first calculation, smallestAngle is still null - in this case it should be assigned the value
                    //(this is probably not very elegant code)
                    if (smallestAngle == null) {
                        smallestAngle = largestLocalAngle;
                        smallestAnglePoint = p;
                    }
                    //we have to find the smallest angle.
                    else if (largestLocalAngle < smallestAngle) {
                        smallestAngle = largestLocalAngle;
                        smallestAnglePoint = p;
                    }
                    //double angleinDegrees = angleInRadians * 180 / Math.PI;
                }
            }
            //TODO if angle a is small enough and point p is not on the boundary

            //create edges e2 and e3 between point p and endpoints of edge e
            Line e2 = new Line {
                X1 = smallestAnglePoint.X,
                Y1 = smallestAnglePoint.Y,
                X2 = longestLine.X1,
                Y2 = longestLine.Y1
            };
            sortedList.Add(e2);
            Line e3 = new Line {
                X1 = smallestAnglePoint.X,
                Y1 = smallestAnglePoint.Y,
                X2 = longestLine.X2,
                Y2 = longestLine.Y2
            };
            sortedList.Add(e3);

            //if edge e2 and e3 don't intersect any other edge
            foreach (Line line in sortedList) {
                Point lineInitialPoint = new Point(line.X1, line.Y1);
                Point lineTerminalPoint = new Point(line.X2, line.Y2);

                Point line2InitialPoint = new Point(e2.X1, e2.Y1);
                Point line2TerminalPoint = new Point(e2.X2, e2.Y2);

                Point line3InitialPoint = new Point(e2.X1, e2.Y1);
                Point line3TerminalPoint = new Point(e2.X2, e2.Y2);

                Point intersectionPoint = GetIntersection(line2InitialPoint, line2TerminalPoint, lineInitialPoint, lineTerminalPoint);
                Point intersectionPoint2 = GetIntersection(line3InitialPoint, line3TerminalPoint, lineInitialPoint, lineTerminalPoint);

                 if ((Double.IsNaN(intersectionPoint.X) && Double.IsNaN(intersectionPoint.Y)) &&
                    (Double.IsNaN(intersectionPoint2.X) && Double.IsNaN(intersectionPoint2.Y))) {
                     //no intersection found, keep rolling..
                     //Console.WriteLine("no intersection found");
                 }
                 else {
                    //intersection found, lines no longer valid
                    Console.WriteLine("intersection found");
                    break;
                 }
                 concaveLineList.Add(e2);
                 concaveLineList.Add(e3);
            }
        }
        //if edge e2 and e3 was not added to list A
        else {
            //add edge e to list B
            concaveLineList.Add(longestLine);
            concavePointCollection.Add(new Point(longestLine.X1, longestLine.Y1));
            concavePointCollection.Add(new Point(longestLine.X2, longestLine.Y2));
        }
    }