public List <Tile> FindPath(Tile startTile, Tile targetTile, int maxDistance, HashSet <Tile.TileState> nonWalkableTiles)
{
// Create the two containers necessary for the pathing algorithm
Heap <PathingTile> openSet = new Heap <PathingTile> (xSize * ySize);
HashSet <PathingTile> closedSet = new HashSet <PathingTile> ();
// Create PathingTile equivalent of the startTile
PathingTile startPath = new PathingTile(startTile);
// Start off by adding the starting location to the openSet
openSet.Add(startPath);
// Loop until the openSet is empty or a path has been found
while (openSet.Count > 0)
{
// Due to our beautiful heap, currentTile is the tile with the current shortest path
PathingTile currentTile = openSet.RemoveFirst();
closedSet.Add(currentTile);
// Wow we found the path! killer.
if (currentTile.location == targetTile.location)
{
return(RetracePath(startPath, currentTile));
}
foreach (Tile neighbor in GetNeighbors(tileMap [currentTile.location.x, currentTile.location.y]))
{
PathingTile neighborTile = new PathingTile(neighbor);
// If we cant walk on it or if we have already checked it, dont add it again to the openSet
if (nonWalkableTiles.Contains(neighbor.curTileState) || closedSet.Contains(neighborTile))
{
continue;
}
int newCostToNeighbor = currentTile.pathWeight + GetTravelCost(tileMap [currentTile.location.x, currentTile.location.y], neighbor);
if (newCostToNeighbor <= maxDistance && (newCostToNeighbor < neighborTile.pathWeight || !openSet.Contains(neighborTile)))
{
neighborTile.pathWeight = newCostToNeighbor;
neighborTile.parent = currentTile;
openSet.Add(neighborTile);
}
}
}
// If we hit this point in the code, no path was found to the target tile
if (debugLogs)
{
Debug.Log("No path found");
}
return(null);
}
List <Tile> RetracePath(PathingTile start, PathingTile end)
{
List <Tile> path = new List <Tile> ();
PathingTile currentTile = end;
// Trace backwards and add all the tiles to path
while (currentTile != start)
{
path.Add(tileMap[currentTile.location.x, currentTile.location.y]);
currentTile = currentTile.parent;
}
// Now path is actually the reversed version of how we want to move, so fix that
path.Reverse();
return(path);
}
