/// <summary>
/// Returns path in start-end order if found, otherwise an empty list
/// </summary>
public static List <Node> FindPath(int startX, int startY, int endX, int endY)
{
int searchID = Random.Range(0, int.MaxValue);
// Variable definition
Node startNode = Grid.GetNode(startX, startY);
Node endNode = Grid.GetNode(endX, endY);
Transform startObject = startNode.nodeObject;
BuildingScript startBs = null;
if (startObject)
{
startBs = startObject.GetComponent <BuildingScript>();
}
if (startBs)
{
if (startBs.HasEntry)
{
startNode = startBs.EntryNode();
}
}
Transform endObject = endNode.nodeObject;
BuildingScript endBs = null;
if (endObject)
{
endBs = endObject.GetComponent <BuildingScript>();
}
Node realEndNode = endNode;
if (endBs)
{
if (endBs.HasEntry)
{
realEndNode = endBs.CenterNode();
endNode = endBs.EntryNode();
}
}
// if (endObject != null && (endObject.tag == "NatureObjectScript" || (endObject.tag == "Building" && endObject.GetComponent<BuildingScript>().GetBuilding().walkable))) endObject = null;
Node currentNode = startNode;
List <Node> path = new List <Node>();
List <Node> openlist = new List <Node>();
// Reset first node
currentNode.Reset(searchID, endX, endY);
// Begin with currentNode = startNode
openlist.Add(currentNode);
currentNode.onOpenList = true;
// Count to prevent stalls
int loopCount = 0;
while (openlist.Count != 0)
{
loopCount++;
if (loopCount > 10000)
{
break;
}
// Get node with minimum F-Value
currentNode = GetMin(openlist);
openlist.RemoveAt(0);
currentNode.onOpenList = false;
//openlist.Remove(currentNode);
// If we have reached the endNode, we have found a path
if (currentNode == endNode)
{
// Bcktrack path to start node
path.Add(currentNode);
while (currentNode != startNode)
{
currentNode = currentNode.GetParent();
path.Add(currentNode);
}
// Return path in start-end order
path.Reverse();
break;
}
// add current node to closed list
currentNode.onClosedList = true;
int cx = currentNode.gridX;
int cy = currentNode.gridY;
// Find neighbours of currentNode
int[] dx = { 1, -1, 0, 0, 1, -1, 1, -1 };
int[] dy = { 0, 0, 1, -1, 1, -1, -1, 1 };
// Weight of diagonal moves are sqrt(2)
float[] weight = { 1, 1.4f };
for (int i = 0; i < 8; i++)
{
// Check if neghbour exists in grid
if (!Grid.ValidNode(cx + dx[i], cy + dy[i]))
{
continue;
}
Node neighbour = Grid.GetNode(cx + dx[i], cy + dy[i]);
if (neighbour.id != searchID)
{
neighbour.Reset(searchID, endX, endY);
}
// Only update neighbour, if not already closed and if walkable
if (neighbour.onClosedList || (!neighbour.IsPath() && (neighbour.IsOccupied() && !neighbour.objectWalkable) &&
(startObject == null || neighbour.nodeObject != startObject || (startBs && startBs.HasEntry)) &&
(endObject == null || neighbour.nodeObject != endObject || (endBs && endBs.HasEntry)) && neighbour != endNode))
{
continue;
}
// Set tentative G-Value
float tg = currentNode.GetG() + weight[i / 4] * currentNode.Weight() * neighbour.Weight();
bool contains = neighbour.onOpenList;
// Only update G-Value of neighbour, if lower
if (contains && tg >= neighbour.GetG())
{
continue;
}
// Update neighbour
neighbour.SetParent(currentNode);
neighbour.SetG(tg);
// Add neighbour to openList if not already contained
if (!contains)
{
InsertNode(openlist, neighbour);
neighbour.onOpenList = true;
}
}
}
// Code for staright path
/*while (true)
* {
* path.Add(currentNode);
*
* int dx = endX - currentNode.gridX;
* int dy = endY - currentNode.gridY;
*
* int dxx = 0; int dyy = 0;
*
* if (dx > 0) dxx = 1;
* else if (dx < 0) dxx = -1;
* if (dy > 0) dyy = 1;
* else if (dy < 0) dyy = -1;
*
* if (dx == 0 && dy == 0) break;
*
* currentNode = Grid.GetNode(currentNode.gridX + dxx, currentNode.gridY + dyy);
* }*/
if (!startBs || !startBs.HasEntry)
{
path.Remove(startNode);
}
/*if (endNode.nodeObject != null && endNode.nodeObject.tag == "Tree")
* {
* path.Remove(endNode);
* }*/
if (realEndNode != endNode && (endBs == null || !endBs.HasEntry))
{
path.Add(realEndNode);
}
return(path);
}