public AStar_Node(TileScript _tileScript, float _gCost, float _hCost, AStar_Node _parent)
{
m_TileScript = _tileScript;
g_cost = _gCost;
h_cost = _hCost;
m_Parent = _parent;
}
public List <TileScript> GetFoundPath(TileScript _startTile, TileScript _endTile, bool ignoreEndNull = true)
{
m_SearchedPath.Clear();
AStar_Node endNodePath = null;
List <AStar_Node> openSet = new List <AStar_Node>();
List <TileScript> openSetTileScript = new List <TileScript>();
HashSet <TileScript> closedSet = new HashSet <TileScript>();
AStar_Node startPathNode = new AStar_Node(_startTile, 0, Vector3.Distance(_startTile.transform.position, _endTile.transform.position), null);
openSet.Add(startPathNode);
openSetTileScript.Add(_startTile);
while (openSet.Count > 0)
{
// get cheapest path
AStar_Node cheapestNode = null;
foreach (AStar_Node node in openSet)
{
if (cheapestNode == null || cheapestNode.f_cost > node.f_cost)
{
cheapestNode = node;
}
}
if (cheapestNode.m_TileScript == _endTile)
{
endNodePath = cheapestNode;
break;
}
// then begin the searching of the neighbours!
List <TileScript> neighbourOfCheapNode = GetNeighbourTiles(cheapestNode.m_TileScript);
foreach (TileScript neighbourTile in neighbourOfCheapNode)
{
// make sure it is not in the open set and it is walkable
if (neighbourTile.TileType == TileScript.TILE_TYPE.WALKABLE && !openSetTileScript.Contains(neighbourTile) && !closedSet.Contains(neighbourTile))
{
// this might not be the correct way to calculate GCost but it works for now
float GCost = Vector3.Distance(_startTile.transform.position, neighbourTile.transform.position) + cheapestNode.g_cost;
float HCost = Vector3.Distance(neighbourTile.transform.position, _endTile.transform.position);
AStar_Node nodePath = new AStar_Node(neighbourTile, GCost, HCost, cheapestNode);
// then we can add it in the open list
openSetTileScript.Add(neighbourTile);
openSet.Add(nodePath);
}
else if (!ignoreEndNull && neighbourTile == _endTile &&
!openSetTileScript.Contains(neighbourTile) && !closedSet.Contains(neighbourTile))
{
// this might not be the correct way to calculate GCost but it works for now
float GCost = Vector3.Distance(_startTile.transform.position, neighbourTile.transform.position) + cheapestNode.g_cost;
float HCost = Vector3.Distance(neighbourTile.transform.position, _endTile.transform.position);
AStar_Node nodePath = new AStar_Node(neighbourTile, GCost, HCost, cheapestNode);
// then we can add it in the open list
openSetTileScript.Add(neighbourTile);
openSet.Add(nodePath);
}
}
closedSet.Add(cheapestNode.m_TileScript);
openSet.Remove(cheapestNode);
openSetTileScript.Remove(cheapestNode.m_TileScript);
}
// then we can start retracing the path
if (endNodePath != null)
{
AStar_Node startTracingNode = endNodePath;
if (!ignoreEndNull)
{
startTracingNode = endNodePath.m_Parent;
}
while (startTracingNode != null)
{
m_SearchedPath.Add(startTracingNode.m_TileScript);
startTracingNode = startTracingNode.m_Parent;
}
// reverse since it is from end to start!
m_SearchedPath.Reverse();
}
return(m_SearchedPath);
}
