// returns the optimal path of a start and end cell, returns empty if path is longer than move speed, or there is no path
public static List <HexCell> GetPath(HexCell begin, HexCell end, int moveSpeed)
{
List <HexCell> path = new List <HexCell>();
OddQPoint goal = new OddQPoint(end);
OddQPoint start = new OddQPoint(begin);
if (SolvePath(MapMaster.Map, start, goal, moveSpeed))
{
OddQPoint step = goal;
while (!step.Equals(start))
{
path.Add(MapMaster.Map[step.r, step.q]);
step = cameFrom[step];
}
path.Reverse();
/*string s = "";
* foreach (HexCell h in path)
* {
* s += h.ToString() + " ";
* }
* Debug.Log(s);*/
}
return(path);
}
//Finds and returns a list of valid neighbors around a given point
private static List <OddQPoint> Neighbors(OddQPoint center)
{
List <OddQPoint> items = new List <OddQPoint>();
int parity = center.q & 1;
OddQPoint n;
foreach (OddQPoint dir in directions[parity])
{
n = new OddQPoint(center.q + dir.q, center.r + dir.r);
if (MapMaster.IsCellOnMap(n.q, n.r))
{
items.Add(n);
}
}
return(items);
}
//Uses A* to solve for the optimal path, bounded by a cost limit
private static bool SolvePath(HexCell[,] map, OddQPoint start, OddQPoint goal, int maxCost)
{
if (!map[goal.r, goal.q].Passable)
{
return(false);
}
cameFrom = new Dictionary <OddQPoint, OddQPoint>();
costSoFar = new Dictionary <OddQPoint, int>();
P_Queue <OddQPoint> openNodes = new P_Queue <OddQPoint>();
openNodes.Enqueue(start, 0);
cameFrom[start] = start;
costSoFar[start] = 0;
OddQPoint current;
while (openNodes.Count != 0) // buid paths until a goal is reached or there is no where else to explore
{
current = openNodes.Dequeue();
if (current.Equals(goal))
{
if (costSoFar[current] > maxCost)
{
return(false);
}
else
{
return(true);
}
}
foreach (OddQPoint next in Neighbors(current))
{
HexCell h = map[next.r, next.q];
if (!h.passable)
{
if (h.unit == null)
{
continue;
}
else if ((h.Unit.Player != PlayerMaster.CurrentTurn))
{
continue;
}
}
int nCost = costSoFar[current] + HexCell.CostToHex(map[current.r, current.q], map[next.r, next.q]);
if (!costSoFar.ContainsKey(next) || nCost < costSoFar[next])
{
costSoFar[next] = nCost;
int prio = nCost + Heuristic(map[next.r, next.q], map[goal.r, goal.q]);
openNodes.Enqueue(next, prio);
cameFrom[next] = current;
}
}
}
return(false);
}
public bool Equals(OddQPoint other)
{
return((other.q == this.q) && (other.r == this.r));
}