private void PathOpened(int x, int y, int newCost, SearchCell parent)
        {
            // Debug.Log(x+","+y);
            if (x < 0 || y < 0)
            {
                return;
            }
            if (x >= GameObject.Find("Main Camera").GetComponent <LoadMap>().m_cols ||
                y >= GameObject.Find("Main Camera").GetComponent <LoadMap>().m_rows)
            {
                return;
            }
            if (GameObject.Find("Main Camera").GetComponent <LoadMap>().Grid[y][x] == 'b')
            {
                return;
            }

            int id = y * WORLD_SIZE + x;

            for (int i = 0; i < scPtr_visitedList.Count; i++)
            {
                if (id == scPtr_visitedList[i].m_id)
                {
                    return;
                }
            }

            SearchCell newChild = new SearchCell(x, y, parent);

            newChild.G = newCost;
            newChild.H = parent.ManHattanDis(scPtr_goalCell);

            for (int i = 0; i < scPtr_openList.Count; i++)
            {
                if (id == scPtr_openList[i].m_id)
                {
                    int newF = newChild.G + newCost + scPtr_openList[i].H;

                    if (scPtr_openList[i].GetF() > newF)
                    {
                        scPtr_openList[i].G           = newChild.G + newCost;
                        scPtr_openList[i].scPtrParent = newChild;
                    }
                    else             //if the new F is not better
                    {
                        return;
                    }
                }
            }

            scPtr_openList.Add(newChild);
        }
        private void SetStartAndGoal(SearchCell start, SearchCell goal)
        {
            SearchCell nullSc = new SearchCell();

            nullSc.m_xcoord = -9999;
            scPtr_startCell = new SearchCell(start.m_xcoord, start.m_ycoord, nullSc);
            scPtr_goalCell  = new SearchCell(goal.m_xcoord, goal.m_ycoord, goal);

            scPtr_startCell.G = 0;
            scPtr_startCell.H = scPtr_startCell.ManHattanDis(scPtr_goalCell);
            //m_startCell.parent = nullptr;

            scPtr_openList.Add(scPtr_startCell);
        }