// Move player to a given tile
public void MoveToTile(GameTile tile)
{
Vector3 newPos = new Vector3(tile.transform.position.x, tile.transform.position.y);
newPos.z = -1;
transform.position = newPos;
GameTile oldTile = map.GetTileAt(curMapPos);
curMapPos = tile.mapPosition;
oldTile.DeOccupy();
tile.Occupy();
costSoFar += pathFinder.distance(oldTile.mapPosition.GetPosition(), tile.mapPosition.GetPosition());
}
public List <GameTile> FindPath()
{
//gameSystem.state = GameState.Paused;
/*
* OPEN: set of nodes to be evaluated
* CLOSED: set of nodes already evaluated
* G: dist of a node from current pos
* H: dist of a node from target pos
* F: G+H
*/
currentTile = mapBehavior.GetTileAt(player.curMapPos);
List <GameTile> OPEN = new List <GameTile>();
List <GameTile> CLOSED = new List <GameTile>();
currentTile.G = 0;
//currentTile.H = currentTile.distance(goalTile);
currentTile.F = currentTile.H + currentTile.G;
OPEN.Add(currentTile);
GameTile current = currentTile;
/*
* loop
* current = node in OPEN with lowest F
* remove current from OPEN
* add current to CLOSED
*
* if current is target node
* return
*/
//int counter = 0; //meant for bounding A*, which ended up not being necessary
//int k = 0;
while (true)
{
float lowestF = Mathf.Infinity;
for (int i = 0; i < OPEN.Count; i++)
{
if (OPEN[i].F < lowestF)
{
lowestF = OPEN[i].F;
current = OPEN[i];
}
}
OPEN.Remove(current);
CLOSED.Add(current);
if (current.mapPosition.GetPosition() == goalTile.mapPosition.GetPosition()) //|| counter > aStarLimit)
{
return(BuildPath(currentTile, current));
}
List <GameTile> neighbours = new List <GameTile>();
//find all appropriate neighbours
Vector2 up = current.mapPosition.GetPosition() + new Vector2(0, 1);
Vector2 down = current.mapPosition.GetPosition() + new Vector2(0, -1);
Vector2 left = current.mapPosition.GetPosition() + new Vector2(1, 0);
Vector2 right = current.mapPosition.GetPosition() + new Vector2(-1, 0);
Vector2 NW = current.mapPosition.GetPosition() + new Vector2(-1, 1);
Vector2 NE = current.mapPosition.GetPosition() + new Vector2(1, 1);
Vector2 SW = current.mapPosition.GetPosition() + new Vector2(-1, -1);
Vector2 SE = current.mapPosition.GetPosition() + new Vector2(1, -1);
Vector2 currentLoc = current.mapPosition.GetPosition();
//add appropriate neighbours
neighbours.Add(mapBehavior.GetTileAt(up));
neighbours.Add(mapBehavior.GetTileAt(down));
neighbours.Add(mapBehavior.GetTileAt(left));
neighbours.Add(mapBehavior.GetTileAt(right));
neighbours.Add(mapBehavior.GetTileAt(NW));
neighbours.Add(mapBehavior.GetTileAt(NE));
neighbours.Add(mapBehavior.GetTileAt(SW));
neighbours.Add(mapBehavior.GetTileAt(SE));
/*
* foreach neighbour of current
* if neighbour is not traversable or neighbour is in CLOSED
* skip to next neighbour
*
* if new path to neighbour is shorter or neighbour is not in OPEN
* set F of neighbour
* set parent of neighbour to current
* if neighbour is not in OPEN
* add neighbour to OPEN
*/
foreach (GameTile n in neighbours)
{
if (!n.isPassable() || CLOSED.Contains(n)) //instead we just check at 0
{
continue;
}
//GameTile is clear for planning
float newNeighbourCost = current.G + distance(current.mapPosition.GetPosition(), n.mapPosition.GetPosition());
if (OPEN.Contains(n) == false || newNeighbourCost < distance(n.mapPosition.GetPosition(), currentLoc))
{
n.G = newNeighbourCost;
n.H = distance(n.mapPosition.GetPosition(), goalTile.mapPosition.GetPosition());
n.F = n.G + n.H;
n.parent = current;
if (!OPEN.Contains(n))
{
OPEN.Add(n);
}
}
}
}
}
