private static Direction GetVisibilityMask(TilePosition position, IDictionary <TilePosition, GroundType> groundTypes)
{
if (!groundTypes.ContainsKey(position))
{
return(Direction.None);
}
if (groundTypes[position].IsInVisible())
{
return(Direction.None);
}
return(position.Neighbors()
.Where(dirAndPos => !HasVisibleNeighbor(groundTypes, dirAndPos.Value))
.Aggregate(Direction.None, (prev, next) => prev.CombineFlags(next.Key)));
}
