Unity_AxisAlignedPolyCheck

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class AxisAlignedPoly
{
    public static bool ContainsPoint(Transform[] polyPoints, Transform Target)
    {
        var j = polyPoints.Length - 1;
        var inside = false;
        Vector3 p = Target.transform.position;

        for (int i = 0; i < polyPoints.Length; j = i++)
        {
            var pi = polyPoints[i].transform.position;
            var pj = polyPoints[j].transform.position;
            if (((pi.z <= p.z && p.z < pj.z) || (pj.z <= p.z && p.z < pi.z)) &&
                (p.x < (pj.x - pi.x) * (p.z - pi.z) / (pj.z - pi.z) + pi.x))
                inside = !inside;
        }
        return inside;
    }
}

public class FenceIn : MonoBehaviour
{
    public Transform[] FencePoints;
    public GameObject Target;

    Material TargetMaterial;

    void Start()
    {
        TargetMaterial = Target.GetComponent<MeshRenderer>().material;
    }

    private void Update()
    {
        if (AxisAlignedPoly.ContainsPoint(FencePoints, Target.transform))
        {
            TargetMaterial.SetColor("_BaseColor", Color.green);
        }
        else
        {
            TargetMaterial.SetColor("_BaseColor", Color.red);
        }

        //DrawConnections(FencePoints);
    }

    public void DrawConnections(Transform[] polyPoints)
    {
        int index = 0;
        while (index < polyPoints.Length-1)
        {
            Vector3 PointA = polyPoints[index].position;
            PointA.y = 0;
            Vector3 PointB = polyPoints[index + 1].position;
            PointB.y = 0;

            Debug.DrawLine(PointA, PointB);
            index += 1;
        }
        if (index == polyPoints.Length-1)
        {
            Vector3 PointA = polyPoints[0].position;
            PointA.y = 0;
            Vector3 PointB = polyPoints[index].position;
            PointB.y = 0;

            Debug.DrawLine(PointA, PointB);
        }
    }
}