public static List <Move> GetChecks(byte[] gamePosition, byte kingColor, List <Move> possibleEnemyMoves)
{
HelperVector2Int tempKing = PieceData.GetKingPosition(gamePosition, kingColor);
HelperVector2Int KingPosition;
if (tempKing != null)
{
KingPosition = tempKing;
}
else
{
return(new List <Move>());
}
return(possibleEnemyMoves.Where(x => x.TargetPosition.x.Equals(KingPosition.x) && x.TargetPosition.y.Equals(KingPosition.y)).ToList());
}
public static int NegaMax(int depth, int alpha, int beta, byte[] gamePosition, byte color, out Move bestmove)
{
bestmove = null;
if (depth == 0)
{
return(EvaluatePosition(gamePosition, color));
}
byte EnemyColor = (color.Equals(PieceData.White)) ? (PieceData.Black) : (PieceData.White);
List <Move> Moves = GetAllPossibleMoves(gamePosition, color, true);
if (Moves.Count == 0)
{
if (PieceData.GetChecks(gamePosition, color, GetAllPossibleMoves(gamePosition, EnemyColor, true)).Any())
{
return(NegInfinity);
}
return(0);
}
int value = NegInfinity;
Move bestMoveout = null;
foreach (Move move in Moves)
{
byte[] tempGamePosition = new byte[64];
Array.Copy(gamePosition, tempGamePosition, gamePosition.Length);
tempGamePosition[move.StartPosition.x + move.StartPosition.y * 8] = PieceData.None;
tempGamePosition[move.TargetPosition.x + move.TargetPosition.y * 8] = move.EndPiece;
int eval = -NegaMax(depth - 1, -beta, -alpha, tempGamePosition, EnemyColor, out bestMoveout);
if (eval >= value)
{
value = eval;
bestmove = move;
}
alpha = (alpha >= value) ? (alpha) : (value);
if (alpha > beta)
{
break;
}
}
return(value);
}
public static List <Move> GetAllPossibleMoves(byte[] gamePosition, byte color, bool CheckForCheck = false)
{
List <Move> PossibleMoves = new List <Move>();
for (int y = 0; y < 8; ++y)
{
for (int x = 0; x < 8; ++x)
{
if (!((gamePosition[x + y * 8] & color) != 0))
{
continue;
}
if ((gamePosition[x + y * 8] & PieceData.Pawn) != 0)
{
PossibleMoves.AddRange(PieceData.GetPawnMoves(gamePosition, new HelperVector2Int(x, y)));
}
if ((gamePosition[x + y * 8] & PieceData.Knight) != 0)
{
PossibleMoves.AddRange(PieceData.GetKnightMoves(gamePosition, new HelperVector2Int(x, y)));
}
if ((gamePosition[x + y * 8] & PieceData.Bishop) != 0)
{
PossibleMoves.AddRange(PieceData.GetBishopMoves(gamePosition, new HelperVector2Int(x, y)));
}
if ((gamePosition[x + y * 8] & PieceData.Rook) != 0)
{
PossibleMoves.AddRange(PieceData.GetRookMoves(gamePosition, new HelperVector2Int(x, y)));
}
if ((gamePosition[x + y * 8] & PieceData.Queen) != 0)
{
PossibleMoves.AddRange(PieceData.GetQueenMoves(gamePosition, new HelperVector2Int(x, y)));
}
if ((gamePosition[x + y * 8] & PieceData.King) != 0)
{
PossibleMoves.AddRange(PieceData.GetKingMoves(gamePosition, new HelperVector2Int(x, y)));
}
}
}
foreach (Move move in PossibleMoves)
{
move.StartPiece += color;
move.EndPiece += color;
}
if (CheckForCheck)
{
byte EnemyColor = (color.Equals(PieceData.White)) ? (PieceData.Black) : (PieceData.White);
List <Move> CheckingMoves = PieceData.GetChecks(gamePosition, color, GetAllPossibleMoves(gamePosition, EnemyColor, false));
List <Move> Remove = new List <Move>();
//if so find move that removes all checking moves
foreach (Move move in PossibleMoves)
{
byte[] AfterMovePossition = new byte[64];
Array.Copy(gamePosition, AfterMovePossition, gamePosition.Length);
AfterMovePossition[move.TargetPosition.x + move.TargetPosition.y * 8] = (move.EndPiece);
AfterMovePossition[move.StartPosition.x + move.StartPosition.y * 8] = PieceData.None;
if (PieceData.GetChecks(AfterMovePossition, color, GetAllPossibleMoves(AfterMovePossition, EnemyColor, false)).Any())
{
Remove.Add(move);
}
}
foreach (Move move in Remove)
{
PossibleMoves.Remove(move);
}
}
return(PossibleMoves);
}
