private Turn CollectHealth(LevelView levelView)
{
if (levelView.Player.Health > HighHealthLimit || !levelView.HealthPacks.Any())
{
automaton.PopAction();
return(automaton.CurrentAction.Invoke(levelView));
}
var influenceMap = InfluenceMap.CreateForm(levelView);
var pathToNearestHealth = PathFinder.FindShortestPathWithInfluenceMap(levelView, influenceMap, levelView.Player.Location, loc => levelView.GetHealthPackAt(loc).HasValue);
return(PathFinder.GetFirstTurn(pathToNearestHealth));
}
public static IEnumerable <Location> Dijkstra(LevelView levelView, Func <Location, bool> isTarget)
{
var costs = new InfluenceMap(levelView);
var current = levelView.Player.Location;
var dist = new Dictionary <Location, int> {
[current] = 0
};
var prev = new Dictionary <Location, Location>();
var notOpened = new HashSet <Location> {
current
};
for (var y = 0; y < levelView.Field.Height; y++)
{
for (var x = 0; x < levelView.Field.Width; x++)
{
var location = new Location(x, y);
var cellType = levelView.Field[location];
if ((cellType == CellType.Empty || cellType == CellType.PlayerStart) && (location != current) &&
!levelView.GetItemAt(location).HasValue)
{
notOpened.Add(location);
dist[location] = int.MaxValue;
}
}
}
while (notOpened.Any())
{
var toOpen = default(Location);
var bestPrice = int.MaxValue;
foreach (var node in notOpened)
{
if (dist.ContainsKey(node) && (dist[node] < bestPrice))
{
bestPrice = dist[node];
toOpen = node;
}
}
notOpened.Remove(toOpen);
if (isTarget(toOpen))
{
return(RevertPath(levelView, toOpen, prev));
}
foreach (var stepOffset in Offset.StepOffsets)
{
var neighbour = toOpen + stepOffset;
if (!notOpened.Contains(neighbour))
{
continue;
}
var alt = dist[toOpen] + costs[neighbour];
if (alt < dist[neighbour])
{
dist[neighbour] = alt;
prev[neighbour] = toOpen;
}
}
}
return(RevertPath(levelView, current, prev));
}
public static List <Location> FindShortestPathWithInfluenceMap(LevelView levelView, InfluenceMap influenceMap, Location from, Func <Location, bool> isTarget)
{
var notOpened = new SortedSet <LocationWithPriority>();
var distances = new Dictionary <Location, int>();
var previous = new Dictionary <Location, Location> {
[from] = default(Location)
};
foreach (var location in levelView.Field.GetAllLocations())
{
if ((IsPassable(location, levelView) || isTarget(location)) && location != from)
{
distances[location] = int.MaxValue;
notOpened.Add(new LocationWithPriority(location, int.MaxValue));
}
}
distances[from] = 0;
notOpened.Add(new LocationWithPriority(from, 0));
while (notOpened.Any())
{
var toOpen = notOpened.Min;
notOpened.Remove(toOpen);
if (toOpen.Priority == int.MaxValue)
{
return(null);
}
if (isTarget(toOpen.Location))
{
return(CreatePath(from, toOpen.Location, previous));
}
foreach (var adjacentLocation in GetAdjacentLocations(toOpen.Location, levelView).Where(l => IsPassable(l, levelView) || isTarget(l)))
{
var currentDistance = toOpen.Priority + influenceMap[adjacentLocation];
if (!previous.ContainsKey(adjacentLocation) || currentDistance < distances[adjacentLocation])
{
notOpened.Remove(new LocationWithPriority(adjacentLocation, distances[adjacentLocation]));
distances[adjacentLocation] = currentDistance;
notOpened.Add(new LocationWithPriority(adjacentLocation, currentDistance));
previous[adjacentLocation] = toOpen.Location;
}
}
}
return(null);
}
