private List <SectorConstrainedPosition> FindPositions(IEnumerable <EnemyMove> moves)
{
List <SectorConstrainedPosition> positions = new List <SectorConstrainedPosition>();
SectorConstrainedPosition currentPosition = new SectorConstrainedPosition(0, 0, null);
positions.Add(currentPosition);
foreach (var move in moves)
{
if (!move.IsMovement && move.HasSector)
{
currentPosition = new SectorConstrainedPosition(currentPosition.X, currentPosition.Y, move.Sector);
positions[positions.Count - 1] = currentPosition;
continue;
}
SectorConstrainedPosition newPosition;
if (move.IsMovement)
{
switch (move.Movement)
{
case Direction.East:
newPosition = new SectorConstrainedPosition(currentPosition.X + 1,
currentPosition.Y,
move.Sector);
break;
case Direction.North:
newPosition = new SectorConstrainedPosition(currentPosition.X,
currentPosition.Y - 1,
move.Sector);
break;
case Direction.South:
newPosition = new SectorConstrainedPosition(currentPosition.X,
currentPosition.Y + 1,
move.Sector);
break;
case Direction.West:
newPosition = new SectorConstrainedPosition(currentPosition.X - 1,
currentPosition.Y,
move.Sector);
break;
default:
throw new InvalidOperationException($"Invalid move {move}");
}
positions.Add(newPosition);
currentPosition = newPosition;
}
}
int xMin = positions.Min(p => p.X);
int yMin = positions.Min(p => p.Y);
int xOffset = xMin < 0 ? Math.Abs(xMin) : 0;
int yOffset = yMin < 0 ? Math.Abs(yMin) : 0;
return(positions.Select(p =>
new SectorConstrainedPosition(p.X + xOffset, p.Y + yOffset, p.SectorConstraint)).ToList());
}
public IEnumerable <Position> LocateEnemy(CancellationToken cancellation, IEnumerable <EnemyMove> moves)
{
if (moves.Count() < 3)
{
return(Enumerable.Empty <Position>());
}
var positions = FindPositions(moves);
var search = new OverlayGrid(_grid.Width, _grid.Height, positions);
Dictionary <Sector, OverlayGrid> sectorGrids =
positions.Where(p => p.IsSectorConstrained)
.GroupBy(p => p.SectorConstraint.Value)
.ToDictionary(p => p.Key,
g => new OverlayGrid(_grid.Width, _grid.Height, g.ToList()));
List <Position> offsetMatches = new List <Position>();
do
{
if (cancellation.IsCancellationRequested)
{
Console.Error.WriteLine("CANCELLING TARGETTING");
break;
}
var mask = search.Mask(_grid.GridBinary);
if (PathDoesNotIntersectWithIslands(mask) &&
NoSectorCollisions(sectorGrids))
{
offsetMatches.Add(search.CurrentOffset);
// Console.Error.WriteLine($"Found a place the enemy could be hiding offset {offset}");
}
if (!search.CanMoveRight && !search.CanMoveDown)
{
break;
}
if (search.CanMoveRight)
{
search.ShiftRight();
foreach (var sectorGrid in sectorGrids.Values)
{
sectorGrid.ShiftRight();
}
continue;
}
search.ShiftToOriginalX();
search.ShiftDown();
foreach (var sectorGrid in sectorGrids.Values)
{
sectorGrid.ShiftToOriginalX();
sectorGrid.ShiftDown();
}
} while (true);
SectorConstrainedPosition lastPosition = positions[positions.Count - 1];
return(offsetMatches.Select(m => new Position(m.X + lastPosition.X, m.Y + lastPosition.Y)));
}
