private static void ProcessPheremoneDecay()
{
for (int x = 0; x < _grid.GetLength(0); x++)
{
for (int y = 0; y < _grid.GetLength(1); y++)
{
Pheromone p = _grid[x, y].Pheromone;
p.Decay();
}
}
}
private void LeavePheremone()
{
Pheromone p = World.Instance.PheremoneAt(X, Y);
if (p.Size < _targetFood.Size * Pheromone.SizeFactor)
{
p.Size = _targetFood.Size * Pheromone.SizeFactor;
}
p.Parent = World.Instance.Grid[_previousNode.X, _previousNode.Y].Pheromone;
}
private Pheromone NearestPheremone()
{
for (int x = Location.X - _searchRadius; x < Location.X + _searchRadius; x++)
{
for (int y = Location.Y - _searchRadius; y < Location.X + _searchRadius; y++)
{
Pheromone p = World.Instance.PheremoneAt(x, y);
if (p.Size >= _pheremoneThreshold)
{
return(p);
}
}
}
return(null);
}
// Manually constructs a path by backtracking over pheremones.
public static Path ConstructPathFromTrail(Pheromone p)
{
Pheromone pToCheck = p;
LinkedList <Node> waypoints = new LinkedList <Node>();
waypoints.AddFirst(World.Instance.Grid[p.X, p.Y]);
LinkedListNode <Node> parentListNode = waypoints.First;
Pheromone parent = World.Instance.PheremoneAt(waypoints.First.Value).Parent;
do
{
Node newNode = World.Instance.Grid[pToCheck.X, pToCheck.Y];
waypoints.AddAfter(parentListNode, newNode);
parentListNode = waypoints.Find(World.Instance.Grid[pToCheck.X, pToCheck.Y]);
pToCheck = parent;
parent = pToCheck.Parent;
// Sometimes pheremone trails will point in loops that don't lead to food.
// If this happens, we simply return a path to a random food object.
if (waypoints.Count > 5000)
{
return(new Path(p.Location, World.Instance.Foods[GameLogic.Random.Next(World.Instance.Foods.Count - 1)].Location));
}
} while (parent != null && !parent.Location.IsAt(pToCheck.Location));
// Once the trail reaches the edge of the food object, finish the path by pathing to the centre of the nearest food.
// This avoids hangs where ants can't quite reach the food and pathfind forever.
Food destination = World.Instance.NearestFood(pToCheck.Location);
Node finalNode = World.Instance.Grid[destination.X, destination.Y];
waypoints.AddAfter(parentListNode, finalNode);
return(new Path(waypoints));
}