How to Repair Argument is Out of Range

Hello, this is the first time I ask in this forum. I hope you all can help me. Thank you.

I really confuse with this error because this is the first I make little bit serious project in unity, so I confuse with the error. This error is appear after the line in screen is drawn.

This is the picture of error :

And this is the code. I use someone code to the draw function and then add code Monotone Chain Convex Hull algorithm for check the convex hull of line which drawn. Anyone can help me please ?

And this is the full code :

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 
 public class DrawLine : MonoBehaviour 
 {
     private LineRenderer line;
     private bool isMousePressed;
     private List<Vector3> pointsList;
     private List<Vector3> H;
     private List<Vector3> simpanConvex;
     private List<Vector3> convexPlus;
     private Vector3 mousePos;
 
     // Structure for line points
     struct myLine
     {
         public Vector3 StartPoint;
         public Vector3 EndPoint;
     };
     //    -----------------------------------    
     void Awake()
     {
         // Create line renderer component and set its property
         line = gameObject.AddComponent<LineRenderer>();
         line.material =  new Material(Shader.Find("Particles/Multiply"));
         line.SetVertexCount(0);
         line.SetWidth(0.1f,0.1f);
         line.SetColors(Color.green, Color.yellow);
         line.useWorldSpace = true;    
         isMousePressed = false;
         pointsList = new List<Vector3>();
 //        renderer.material.SetTextureOffset(
     }
     //    -----------------------------------    
     void Update () 
     {
         // If mouse button down, remove old line and set its color to green
         if(Input.GetMouseButtonDown(0))
         {
             isMousePressed = true;
             line.SetVertexCount(0);
             pointsList.RemoveRange(0,pointsList.Count);
             line.SetColors(Color.green, Color.yellow);
         }
         else if(Input.GetMouseButtonUp(0))
         {
             isMousePressed = false;
         }
         // Drawing line when mouse is moving(presses)
         if(isMousePressed)
         {
             mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
             mousePos.z=0;
             if (!pointsList.Contains (mousePos)) 
             {
                 pointsList.Add (mousePos);
                 line.SetVertexCount (pointsList.Count);
                 line.SetPosition (pointsList.Count - 1, (Vector3)pointsList [pointsList.Count - 1]);
                 if(isLineCollide())
                 {
                     isMousePressed = false;
                     line.SetColors(Color.red, Color.red);
 
                     //proses Algoritma
                     simpanConvex = new List<Vector3>();
                     simpanConvex = convex_hull(pointsList);
                     pointsList.Add (new Vector3(2.23f,-0.89f,0));
                     convexPlus = new List<Vector3>();
                     convexPlus = convex_hull(pointsList);
 
                     //proses cek objek di dalam atau di luar
                     for (int i = 0; i < convexPlus.Count; i++)
                     {
                         if ((simpanConvex[i].x == convexPlus[i].x) && (simpanConvex[i].y == convexPlus[i].y))
                         {
                             Debug.Log ("Didalam");
                         }
                         else
                         {
                             Debug.Log ("Diluar");
                         }
                     }
                 }
             }
         }
     }
     //    -----------------------------------    
     //  Following method checks is currentLine(line drawn by last two points) collided with line 
     //    -----------------------------------    
     private bool isLineCollide()
     {
         if (pointsList.Count < 2)
             return false;
         int TotalLines = pointsList.Count - 1;
         myLine[] lines = new myLine[TotalLines];
         if (TotalLines > 1) 
         {
             for (int i=0; i<TotalLines; i++) 
             {
                 lines [i].StartPoint = (Vector3)pointsList [i];
                 lines [i].EndPoint = (Vector3)pointsList [i + 1];
             }
         }
         for (int i=0; i<TotalLines-1; i++) 
         {
             myLine currentLine;
             currentLine.StartPoint = (Vector3)pointsList [pointsList.Count - 2];
             currentLine.EndPoint = (Vector3)pointsList [pointsList.Count - 1];
             if (isLinesIntersect (lines [i], currentLine)) 
                 return true;
         }
         return false;
     }
     //    -----------------------------------    
     //    Following method checks whether given two points are same or not
     //    -----------------------------------    
     private bool checkPoints (Vector3 pointA, Vector3 pointB)
     {
         return (pointA.x == pointB.x && pointA.y == pointB.y);
     }
     //    -----------------------------------    
     //    Following method checks whether given two line intersect or not
     //    -----------------------------------    
     private bool isLinesIntersect (myLine L1, myLine L2)
     {
         if (checkPoints (L1.StartPoint, L2.StartPoint) ||
             checkPoints (L1.StartPoint, L2.EndPoint) ||
             checkPoints (L1.EndPoint, L2.StartPoint) ||
             checkPoints (L1.EndPoint, L2.EndPoint))
             return false;
         
         return((Mathf.Max (L1.StartPoint.x, L1.EndPoint.x) >= Mathf.Min (L2.StartPoint.x, L2.EndPoint.x)) &&
                (Mathf.Max (L2.StartPoint.x, L2.EndPoint.x) >= Mathf.Min (L1.StartPoint.x, L1.EndPoint.x)) &&
                (Mathf.Max (L1.StartPoint.y, L1.EndPoint.y) >= Mathf.Min (L2.StartPoint.y, L2.EndPoint.y)) &&
                (Mathf.Max (L2.StartPoint.y, L2.EndPoint.y) >= Mathf.Min (L1.StartPoint.y, L1.EndPoint.y)) 
                );
     }
 
     //fungsi cross algoritma
     private double cross (Vector3 o, Vector3 a, Vector3 b)
     {
         return ((a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x));
     }
 
     //fungsi sort
     private int Vector3Compare (Vector3 v1, Vector3 v2)
     {
         if (v1.x < v2.x) {
             return -1;
         } else if (v1.x == v2.x) {
             if (v1.y < v2.y) {
                 return -1;
             } else if (v1.y == v2.y) {
                 if (v1.z < v2.z) {
                     return -1;
                 } else if (v1.z == v2.z) {
                     return 0;
                 } else {
                     return 1;
                 }
             } else {
                 return 1;
             }
         } else {
             return 1;
         }
     }
 
     //fungsi Algoritma
     private List<Vector3> convex_hull (List<Vector3> listCome)
     {
         int n = listCome.Count;
         int k = 0;
         H = new List<Vector3>();
         //sort
         //listCome.Sort ();
         //listCome = listCome.OrderBy (v => v.x).OrderByDescending (v => v.y);
         listCome.Sort (Vector3Compare);
         //build lower hull
         for (int i = 0; i < n; i++) {
             while (k >= 2 && cross(H[k-2], H[k-1], listCome[i]) <= 0) k--;
             H[k++] = listCome[i];
         }
 
         //build upper hull
         for (int i = n-2, t = k+1; i >= 0; i--) {
             while (k >= t && cross(H[k-2], H[k-1], listCome[i]) <= 0) k--;
             H[k++] = listCome[i];
         }
         //resize dipertanyakan
         //H.Capacity.Equals (k);
 
         return H;
     }
 
 }