private static bool isGoalReachable(CollisionMap Map)
{
List <CollisionMapElement> neighboursToCheck = Map.getElement(Map.GoalPosition).getUnblockedNeighbours();
List <CollisionMapElement> elementList = new List <CollisionMapElement>();
//Debug.Log("isGoalReachable");
while (neighboursToCheck.Except(elementList).Count() > 0)
{
CollisionMapElement target = neighboursToCheck[0];
if (!elementList.Contains(target))
{
elementList.Add(target);
}
List <CollisionMapElement> neighbours = target.getUnblockedNeighbours();
if (
neighboursToCheck.Except(neighbours).Count() != 0 &&
elementList.Intersect(neighbours).Count() != neighbours.Count()
)
{
neighboursToCheck.AddRange(neighbours.Except(neighboursToCheck).ToList());
}
neighboursToCheck.Remove(target);
}
//Map.printMap();
//Debug.Log("end isGoalReachable");
return(elementList.Any(element => element.ElementCoordinate.Equals(Map.CurrentPosition)));
}
private static PlayerMovementPath getCachedSolution(CollisionMap Map)
{
if (cachedSolutions.Count == 0)
{
return(null);
}
//Debug.Log(cachedSolutions.Count);
return(cachedSolutions.Find(path => path.StartCoordinate.Equals(Map.CurrentPosition) && path.GoalCoordinate.Equals(Map.GoalPosition)));
}
public override bool Equals(System.Object map)
{
// There is no map
if (map == null)
{
return(false);
}
// Wrong type
if (!map.GetType().IsAssignableFrom(this.GetType()))
{
return(false);
}
CollisionMap targetMap = (CollisionMap)map;
// Player is at a different coordinate
if (!targetMap.CurrentPosition.Equals(this.CurrentPosition))
{
return(false);
}
// Are the blocks the same?
for (int i = 0; i >= this.Width - 1; i++)
{
for (int j = 0; j >= this.Height; j++)
{
if (targetMap.getElement(new Coordinate(i, j)).Blocked != this.getElement(new Coordinate(i, j)).Blocked)
{
return(false);
}
}
}
return(true);
}
public static PlayerMovementPath ProcessSolution(CollisionMap Map)
{
PlayerMovementPath currentPath = null;
List <PlayerMovementPath> statesToCheck = new List <PlayerMovementPath>();
PlayerMovementPath solution = null;
// If we have this map saved, we can attempt to get the solution from cache
if (Map.Equals(targetMap))
{
// Attempt to get it from cache
solution = getCachedSolution(Map);
if (solution != null)
{
//return solution;
}
}
else
{
targetMap = Map;
cachedSolutions.Clear();
}
if (!isGoalReachable(Map))
{
return(null);
}
int stateCount = 0;
//Debug.Log("ProcessSolution");
while (true)
{
if (currentPath == null)
{
currentPath = new PlayerMovementPath();
currentPath.CoordinatePath.Add(Map.CurrentPosition);
currentPath.HeuristicValue = Map.getElement(Map.CurrentPosition).DistanceFromGoal;
}
else
{
if (statesToCheck.Count() == 0)
{
// If we have searched through all possible states, we cannot reach goal. End
break;
}
int heuristicValue = statesToCheck.Min(path => path.HeuristicValue);
currentPath = statesToCheck.Where(path => path.HeuristicValue == heuristicValue).FirstOrDefault();
// Do not need to check any states that are currently looking at this position
statesToCheck.RemoveAll(path => path.LastCoordinate == currentPath.LastCoordinate);
}
// We have found the solution
if (Map.GoalPosition.Equals(currentPath.getLastCoordinate()))
{
solution = currentPath;
break;
}
stateCount++;
// Add all states to the list
statesToCheck.AddRange(createProposedMovementPaths(currentPath, Map));
}
//Debug.Log("ProcessSolution end");
if (solution != null)
{
solution.CoordinatePath.RemoveAt(0);
solution.StartCoordinate = Map.CurrentPosition;
solution.GoalCoordinate = Map.GoalPosition;
//Debug.Log("adding solution");
cachedSolutions.Add(solution);
}
return(solution);
}
private static List <PlayerMovementPath> createProposedMovementPaths(PlayerMovementPath currentMovementPath, CollisionMap Map)
{
List <PlayerMovementPath> paths = new List <PlayerMovementPath>();
// Get the unblocked neighbours at the current coordinate
List <CollisionMapElement> childElements = Map.getElement(currentMovementPath.getLastCoordinate()).getUnblockedNeighbours();
foreach (CollisionMapElement element in childElements)
{
// Do not go back the direction you just came
if (!element.ElementCoordinate.Equals(currentMovementPath.getSecondToLastCoordinate()))
{
PlayerMovementPath newMovementPath = currentMovementPath.Clone();
// Add the other coordinates
newMovementPath.CoordinatePath.Add(element.ElementCoordinate);
newMovementPath.HeuristicValue = Map.getElement(element.ElementCoordinate).DistanceFromGoal + currentMovementPath.getDistanceTravelled();
paths.Add(newMovementPath);
}
}
return(paths);
}