public float GetHeuristic(MazeNode nodeStart, MazeNode nodeEnd, AStarMode mode, float rand = 0f)
{
Vector2 start = new Vector2(nodeStart.transform.position.x, nodeStart.transform.position.z);
Vector2 end = new Vector2(nodeEnd.transform.position.x, nodeEnd.transform.position.z);
if (mode == AStarMode.euclidian) {
return Vector2.Distance(start, end);
}
if (mode == AStarMode.manhattan) {
return Mathf.Abs(start.x - end.x) + Mathf.Abs(start.y - end.y);
}
if (mode == AStarMode.randomEuclidian) {
return Vector2.Distance(start, end) + Random.Range(0f, rand);
}
if (mode == AStarMode.randomManhattan) {
return Mathf.Abs(start.x - end.x) + Mathf.Abs(start.y - end.y) + Random.Range(0f, rand);
}
else {
Debug.LogWarning("Unspecified Heuristic!");
return 0f;
}
}
IEnumerator AStarAgent(AStarMode mode = AStarMode.manhattan, float rand = 5f)
{
int timer = 0;
List<MazeNode> closed = new List<MazeNode>();
List<MazeNode> open = new List<MazeNode>();
open.Add(startNode);
startNode.g = 0f;
while (open.Count > 0) {
MazeNode bestNode = open[0];
foreach (MazeNode node in open) {
if (node.f < bestNode.f) {
bestNode = node;
}
}
if (bestNode == exitNode) {
break;
}
foreach (MazeNode node in bestNode.currentConnections) {
if (node == null) {
continue;
}
if (node.closed) {
continue;
}
open.Add(node);
float newG = bestNode.g + GetHeuristic(bestNode, node, AStarMode.manhattan, 0f);
if (node.g > newG) {
node.g = newG;
node.h = GetHeuristic(node, exitNode, mode, rand);
node.f = node.g + node.h;
node.cameFrom = bestNode;
}
}
closed.Add(bestNode);
bestNode.closed = true;
if (debugColors) {
bestNode.floorRenderer.material = debugCyan;
}
open.Remove(bestNode);
timer++;
if (timer >= aStarSpeed) {
timer = 0;
yield return new WaitForSeconds(0.01f);
}
}
//Reset came from
foreach(MazeNode node in closed) {
node.ResetAStarVariables();
}
foreach(MazeNode node in open) {
node.ResetAStarVariables();
}
yield break;
}
public List<MazeNode> AStar(MazeNode start, MazeNode end, AStarMode mode = AStarMode.manhattan, float rand = 5f, bool ignoreWalls = false)
{
List<MazeNode> path = new List<MazeNode>();
List<MazeNode> closed = new List<MazeNode>();
List<MazeNode> open = new List<MazeNode>();
open.Add(start);
start.g = 0f;
while (open.Count > 0) {
MazeNode bestNode = open[0];
foreach (MazeNode node in open) {
if (node.f < bestNode.f) {
bestNode = node;
}
}
if (bestNode == end) {
break;
}
if (ignoreWalls) {
foreach (MazeNode node in bestNode.connections) {
if (node == null) {
continue;
}
if (node.closed) {
continue;
}
open.Add(node);
float newG = bestNode.g + GetHeuristic(bestNode, node, AStarMode.manhattan, 0f);
if (node.g > newG) {
node.g = newG;
node.h = GetHeuristic(node, end, mode, rand);
node.f = node.g + node.h;
node.cameFrom = bestNode;
}
}
}
else {
foreach (MazeNode node in bestNode.currentConnections) {
if (node == null) {
continue;
}
if (node.closed) {
continue;
}
open.Add(node);
float newG = bestNode.g + GetHeuristic(bestNode, node, AStarMode.manhattan, 0f);
if (node.g > newG) {
node.g = newG;
node.h = GetHeuristic(node, end, mode, rand);
node.f = node.g + node.h;
node.cameFrom = bestNode;
}
}
}
closed.Add(bestNode);
bestNode.closed = true;
open.Remove(bestNode);
}
//Determine path
path.Add(end);
MazeNode next = end;
while (next != start) {
next = next.cameFrom;
path.Add(next);
}
path.Reverse();
//Reset came from
foreach(MazeNode node in closed) {
node.ResetAStarVariables();
}
foreach(MazeNode node in open) {
node.ResetAStarVariables();
}
return path;
}
