private void GetValidSlides(PieceName target, Position currentPosition, HashSet <Position> visitedPositions, int currentRange, int?maxRange, MoveSet validMoves)
{
if (!maxRange.HasValue || currentRange < maxRange.Value)
{
for (int slideDirection = 0; slideDirection < EnumUtils.NumDirections; slideDirection++)
{
Position slidePosition = currentPosition.NeighborAt(slideDirection);
if (!visitedPositions.Contains(slidePosition) && !HasPieceAt(slidePosition))
{
// Slide position is open
int right = EnumUtils.RightOf(slideDirection);
int left = EnumUtils.LeftOf(slideDirection);
if (HasPieceAt(currentPosition.NeighborAt(right)) != HasPieceAt(currentPosition.NeighborAt(left)))
{
// Can slide into slide position
Move move = new Move(target, slidePosition);
if (validMoves.Add(move))
{
// Sliding from this position has not been tested yet
visitedPositions.Add(move.Position);
GetValidSlides(target, slidePosition, visitedPositions, currentRange + 1, maxRange, validMoves);
}
}
}
}
}
}
private MoveSet GetValidBeetleMovements(Piece targetPiece)
{
MoveSet validMoves = new MoveSet();
// Look in all directions
for (int direction = 0; direction < EnumUtils.NumDirections; direction++)
{
Position newPosition = targetPiece.Position.NeighborAt(direction);
Piece topNeighbor = GetPieceOnTopInternal(newPosition);
// Get positions to left and right or direction we're heading
int leftOfTarget = EnumUtils.LeftOf(direction);
int rightOfTarget = EnumUtils.RightOf(direction);
Position leftNeighborPosition = targetPiece.Position.NeighborAt(leftOfTarget);
Position rightNeighborPosition = targetPiece.Position.NeighborAt(rightOfTarget);
Piece topLeftNeighbor = GetPieceOnTopInternal(leftNeighborPosition);
Piece topRightNeighbor = GetPieceOnTopInternal(rightNeighborPosition);
// At least one neighbor is present
uint currentHeight = targetPiece.Position.Stack + 1;
uint destinationHeight = null != topNeighbor ? topNeighbor.Position.Stack + 1 : 0;
uint topLeftNeighborHeight = null != topLeftNeighbor ? topLeftNeighbor.Position.Stack + 1 : 0;
uint topRightNeighborHeight = null != topRightNeighbor ? topRightNeighbor.Position.Stack + 1 : 0;
// "Take-off" beetle
currentHeight--;
if (!(currentHeight == 0 && destinationHeight == 0 && topLeftNeighborHeight == 0 && topRightNeighborHeight == 0))
{
// Logic from http://boardgamegeek.com/wiki/page/Hive_FAQ#toc9
if (!(destinationHeight < topLeftNeighborHeight && destinationHeight < topRightNeighborHeight && currentHeight < topLeftNeighborHeight && currentHeight < topRightNeighborHeight))
{
Position targetPosition = (newPosition.Stack == destinationHeight) ? newPosition : topNeighbor.Position.GetAbove();
Move targetMove = new Move(targetPiece.PieceName, targetPosition);
validMoves.Add(targetMove);
}
}
}
return(validMoves);
}
