public static unsafe int GetShortestPathToOutsideLength(Point startPoint, Direction direction, PointsSet territory)
{
var queue = stackalloc int[GameParams.MapSize.Width * GameParams.MapSize.Height];
int queueHead = 0;
int queueTail = 0;
var visited = stackalloc bool[GameParams.MapSize.Width * GameParams.MapSize.Height];
var moves = stackalloc int[GameParams.MapSize.Width * GameParams.MapSize.Height];
visited[startPoint.X + startPoint.Y * GameParams.MapSize.Width] = true;
moves[startPoint.X + startPoint.Y * GameParams.MapSize.Width] = 0;
queue[queueHead++] = startPoint.X + startPoint.Y * GameParams.MapSize.Width;
while (queueTail != queueHead)
{
int coord = queue[queueTail++];
var point = new Point(coord % GameParams.MapSize.Width, coord / GameParams.MapSize.Width);
int currentPathLength = moves[coord];
foreach (var neighbor in point.GetNeighbors())
{
int neighborCoord = neighbor.X + neighbor.Y * GameParams.MapSize.Width;
if (!GameParams.MapSize.ContainsPoint(neighbor) || visited[neighborCoord] ||
currentPathLength == 0 && neighbor == startPoint.MoveLogic(direction.GetOpposite()))
{
continue;
}
if (!territory.Contains(neighbor))
{
return(currentPathLength + 1);
}
visited[neighborCoord] = true;
moves[neighborCoord] = currentPathLength + 1;
queue[queueHead++] = neighborCoord;
}
}
return(-1);
}
public static PointsSet GetBoundary(this PointsSet pointsSet)
{
return(new PointsSet(pointsSet.Where(p => p.GetEightNeighbors().Any(n => !pointsSet.Contains(n)))));
}
