Building roads unity

using UnityEngine;
using System.Collections;
using Pathfinding;

public class BuildRoad : MonoBehaviour {

    public GameObject dirtRoad;
    public GameObject nodeControl;
    GameObject road;
    GameObject node;

    public LayerMask acceptableLayer;

    public bool buildingRoad;
    bool currentlyBuilding;

    Vector3 roadStartLocation;
    float roadLength;

    float gridSize;
    SaveManager save;

    void Start()
    {
        gridSize = 5f;
        save = GameObject.Find("CameraControl").GetComponent<SaveManager>();
    }

    void Update()
    {

        if(buildingRoad)
        {
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit = new RaycastHit();

            if(Physics.Raycast(ray, out hit, Mathf.Infinity, acceptableLayer))
            {
                int x = Mathf.FloorToInt(hit.point.x / gridSize);
                int z = Mathf.FloorToInt(hit.point.z / gridSize);

                node.transform.position = new Vector3(x * gridSize, hit.point.y, z * gridSize);
            }

            if(Input.GetMouseButtonDown(0))
            {
                currentlyBuilding = true;
                //ClickLocation(out roadStartLocation);
                road = Instantiate (dirtRoad) as GameObject;
                road.transform.position = node.transform.position + new Vector3(0, 0.1f, 0);
            }

            if(currentlyBuilding)
            {
                roadLength = updateRoadLive(road.transform.position, road);
            }

            if(Input.GetMouseButtonUp(0) && currentlyBuilding)
            {

                TerrainHelper.updateTextureWithinBounds(road);
                road.GetComponent<MeshRenderer>().enabled = false;
                BoxCollider boxCol = road.GetComponent<BoxCollider>();
                boxCol.size = new Vector3(boxCol.size.x, 1f, 1f);
                MyGUO guo = new MyGUO();
                guo.bounds = road.collider.bounds;
                guo.setPenalty = 0;
                guo.modifyTag = true;
                guo.setTag = 1;
                AstarPath.active.UpdateGraphs(guo);
                save.addObjectToGoList(road);
                road.GetComponent<RoadScript>().length = roadLength;
                road.GetComponent<RoadScript>().FindObstacles();

                currentlyBuilding = false;
            }

            if(Input.GetMouseButtonDown(1) && currentlyBuilding)
            {
                Destroy(road);
                currentlyBuilding = false;
            }
            if(Input.GetMouseButtonDown(1) && !currentlyBuilding)
            {
                Destroy(node);
                buildingRoad = false;
            }
        }


    }

    bool ClickLocation(out Vector3 point)
    {
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        RaycastHit hit = new RaycastHit();

        if(Physics.Raycast(ray, out hit, Mathf.Infinity, acceptableLayer))
        {
            point = hit.point;
            return true;
        }
        point = Vector3.zero;
        return false;
    }

    void OnTriggerEnter(Collider otherCollider)
    {

    }

    float updateRoadLive(Vector3 roadStart, GameObject roadTemp)
    {
        Vector3 roadEnd = roadStart;

        roadEnd = node.transform.position + new Vector3(0, 0.1f, 0);
        roadTemp.transform.rotation = Quaternion.FromToRotation(Vector3.right, roadEnd - roadStart);

        Vector3 rot = road.transform.eulerAngles;
        rot.y = Mathf.Round (rot.y / 90) * 90;
        roadTemp.transform.eulerAngles = rot;

        float length = Mathf.Clamp(Vector3.Distance(roadEnd, roadStart), 2.5f, Mathf.Infinity) + 2.5f;

        float width = 5;

        Vector3[] vertices = {
            new Vector3(-2.5f,      0, -width/2),
            new Vector3(length, 0, -width/2),
            new Vector3(length, 0, width/2),
            new Vector3(-2.5f,      0, width/2)
        };

        int[] triangles = {
            1, 0, 2,
            2, 0, 3
        };

        Vector2[] uv = {
            new Vector2(-2.5f, -width/2),
            new Vector2(length, -width/2),
            new Vector2(length, width/2),
            new Vector2(-2.5f, width/2)
        };

        Vector3[] normals = {
            Vector3.up,
            Vector3.up,
            Vector3.up,
            Vector3.up
        };

        Vector4[] tangent = {
            new Vector4(1f, 0f, 0f, 1f),
            new Vector4(1f, 0f, 0f, 1f),
            new Vector4(1f, 0f, 0f, 1f),
            new Vector4(1f, 0f, 0f, 1f)
        };

        Mesh mesh = new Mesh();

        mesh.vertices = vertices;
        mesh.triangles = triangles;
        mesh.uv = uv;
        mesh.normals = normals;
        //mesh.RecalculateNormals();
        mesh.tangents = tangent;
        mesh.name = "Road";

        MeshFilter mesh_filter = road.GetComponent<MeshFilter>();
        mesh_filter.mesh = mesh;

        BoxCollider boxCol = roadTemp.GetComponent<BoxCollider>();
        boxCol.size = new Vector3(length + 2.5f, 1f, 5f);
        boxCol.center = new Vector3((length - 2.5f) / 2 , 0f, 0f);

        return length;
    }

    public void startBuildingRoad()
    {
        buildingRoad = true;
        node = (GameObject)Instantiate (nodeControl, Vector3.zero, Quaternion.identity);
    }


}