Hello again Nina!
Thank you for your help.
I have done what i was aiming to, but there is still an error shows up when i click again to create another path, the same error shows if the start and end waypoints are the same.
the previous waypoint gets to be null in the second time i try to draw a new path.
here is the code:
public class PathFinder : MonoBehaviour
{
[SerializeField] Waypoint startWaypoint, endWaypoint;
public Dictionary<Vector2Int, Waypoint> grid = new Dictionary<Vector2Int, Waypoint>();
public Queue<Waypoint> queue = new Queue<Waypoint>();
bool isRunning = true;
public Waypoint searchCenter;
public Waypoint previous;
public List<List<Waypoint>> paths = new List<List<Waypoint>>();
Vector2Int[] directions = {
Vector2Int.up,
Vector2Int.right,
Vector2Int.down,
Vector2Int.left
};
private void Start()
{
LoadBlocks();
//CalculatePath();
//ColorThePath(path);
}
private void Update()
{
ClickToSelectStartPoint();
ClickToSelectEndPoint();
// CalculatePath();
// ColorThePath(path);
}
void ColorThePath(List<Waypoint> path)
{
foreach (Waypoint wp in path)
{
wp.SetTopColor(Color.cyan);
}
}
// Start is called before the first frame update
public void CalculatePath()
{
BreadthFirstSearch();
paths.Add(CreatePath());
}
private List<Waypoint> CreatePath()
{
List<Waypoint> path = new List<Waypoint>();
path.Add(endWaypoint);
previous = endWaypoint.exploredFrom;
while (previous != startWaypoint)
{
path.Add(previous);
previous = previous.exploredFrom;
}
path.Add(startWaypoint);
path.Reverse();
ColorThePath(path);
return path;
}
private void BreadthFirstSearch()
{
queue.Enqueue(startWaypoint);
searchCenter = startWaypoint;
while (queue.Count > 0 && isRunning)
{
searchCenter = queue.Dequeue();
HaltIfEndFound();
ExploreNeighbours();
searchCenter.isExplored = true;
}
}
private void HaltIfEndFound()
{
if (searchCenter == endWaypoint)
{
isRunning = false;
}
}
private void ExploreNeighbours()
{
if (!isRunning) { return; }
foreach (Vector2Int direction in directions)
{
Vector2Int neighbourCoordinates = searchCenter.GetGridPos() + direction;
if (grid.ContainsKey(neighbourCoordinates))
{
QueueNewNeighbours(neighbourCoordinates);
}
}
}
private void QueueNewNeighbours(Vector2Int neighbourCoordinates)
{
Waypoint neighbour = grid[neighbourCoordinates];
if (neighbour.isExplored || queue.Contains(neighbour))
{
// do nothing
}
else
{
queue.Enqueue(neighbour);
neighbour.exploredFrom = searchCenter;
}
}
public void ClickToSelectStartPoint()
{
if (Input.GetMouseButtonDown(0))
{
startWaypoint = null;
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100.0f))
{
if (hit.transform.tag == "WayPoint")
{
GameObject block = hit.transform.gameObject;
print(block.name + " Is Clicked");
Waypoint startPoint = block.GetComponentInParent<Waypoint>();
print(startPoint.name + "This is startpoint");
startWaypoint = startPoint;
startWaypoint.SetTopColor(Color.green);
searchCenter = startWaypoint;
searchCenter.exploredFrom = null;
}
else
{
//DoNothing
}
}
}
}
public void ClickToSelectEndPoint()
{
if (Input.GetMouseButtonUp(0))
{
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100.0f))
{
if (hit.transform.tag == "WayPoint")
{
GameObject block = hit.transform.gameObject;
print(block.name + " Is Clicked");
Waypoint endPoint = block.GetComponentInParent<Waypoint>();
print(endPoint.name + "This is End point");
endWaypoint = endPoint;
endWaypoint.SetTopColor(Color.green);
}
else
{
//DoNothing
}
}
CalculatePath();
}
}
public void LoadBlocks()
{
var waypoints = FindObjectsOfType<Waypoint>();
foreach (Waypoint waypoint in waypoints)
{
var gridPos = waypoint.GetGridPos();
if (grid.ContainsKey(gridPos))
{
Debug.LogWarning("Skipping overlapping block " + waypoint);
}
else
{
grid.Add(gridPos, waypoint);
}
}
}
}
