public Vector3 generatePath(Vector3 _position, Vector3 _target, ref List <Vector3> _path)
{
int count = 0;
if (collisionMap.CollisionTable == null)
{
return(Vector3.zero);
}
// if _target not walkable, re-compute to closer walkable node
// if _start not walkable something bad happened, break and debug
// create start node
int startX = (int)_position.x;
int startY = (int)-_position.y;
Node startNode = new Node(!collisionMap.CheckCollision(startX, startY), startX, startY);
if (!startNode.walkable)
{
Debug.Log("Unwalkable start node.");
return(Vector3.zero);
}
// create target node
int targetX = (int)_target.x;
int targetY = (int)-_target.y;
Node targetNode = new Node(!collisionMap.CheckCollision(targetX, targetY), targetX, targetY);
// if target not walkable, consider moving target to closest walkable node
Heap <Node> openSet = new Heap <Node>(collisionMap.MapWidth * collisionMap.MapHeight * 10);
List <Node> closedSet = new List <Node>();
openSet.Add(startNode);
// main loop
while (openSet.Count > 0)
{
count++;
if (count >= breakCount)
{
return(Vector3.zero);
}
// get node in openSet with lowest fCost
Node current = openSet.RemoveFirst();
closedSet.Add(current);
// check if we found target Node
if (current.Equals(targetNode))
{
Debug.Log("Path found: " + new Vector3(current.x, current.y, 0.0f));
_path = ReconstructPath(current);
return(new Vector3(current.x, current.y, 0.0f));
}
for (int i = 0; i < dirMap.Length; i++)
{
// create new Nodes based on dir and check for collision
int neighX = current.x + dirMap[i].x;
int neighY = current.y + dirMap[i].y;
Node neighbour = new Node(!collisionMap.CheckCollision(neighX, neighY), neighX, neighY);
if (!neighbour.walkable)
{
continue;
}
if (closedSet.Contains(neighbour))
{
continue;
}
int tempGScore = current.gCost + 1;
if (tempGScore < neighbour.gCost || !openSet.Contains(neighbour))
{
neighbour.gCost = tempGScore;
neighbour.hCost = GetDistance(neighbour, targetNode);
neighbour.parent = current;
if (!openSet.Contains(neighbour))
{
openSet.Add(neighbour);
}
else
{
openSet.UpdateItem(neighbour);
}
}
}
}
// failed
Debug.Log("No path found");
return(Vector3.zero);
}