public Move GetMove(Int32 startSquare, Int32 endSquare, Player player)
{
List<Move> moves = engine.FindMoves(board, player.Color.ToString());
for (var i = 0; i < moves.Count; i++)
{
var move = moves[i];
if (move.StartSquare == (Byte)startSquare && move.EndSquare == (Byte)endSquare)
{
// same piece must jump rule
if (player.Type == Player.PlayerType.HUMAN)
{
if (move.HasChildMoves)
mustJumpFromSquare = move.EndSquare;
else
mustJumpFromSquare = 0;
}
return move;
}
}
return null;
}
public Boolean IsMoveLegal(Int32 startSquare, Int32 endSquare, Player player)
{
List<Move> moves = engine.FindMoves(board, player.Color.ToString());
for (var i = 0; i < moves.Count; i++)
{
var move = moves[i];
// force same piece jumping
if (player.Type == Player.PlayerType.HUMAN)
if (mustJumpFromSquare > 0 && move.StartSquare != mustJumpFromSquare)
continue;
if (move.StartSquare == (Byte)startSquare && move.EndSquare == (Byte)endSquare)
return true;
}
return false;
}
private void ChangeCurrentPlayer()
{
if (currentPlayer == redPlayer)
currentPlayer = whitePlayer;
else
currentPlayer = redPlayer;
}
private void StartNewGame()
{
board = new Byte[] {
0,2,0,2,0,2,0,2,
2,0,2,0,2,0,2,0,
0,2,0,2,0,2,0,2,
0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,
1,0,1,0,1,0,1,0,
0,1,0,1,0,1,0,1,
1,0,1,0,1,0,1,0};
ai = new AI();
engine = new MoveEngine(board);
redPlayer = new Player(Player.PlayerColor.RED, Player.PlayerType.COMPUTER);
whitePlayer = new Player(Player.PlayerColor.WHITE, Player.PlayerType.HUMAN);
currentPlayer = whitePlayer;
gameOver = false;
pbTurnSignal.BackColor = Color.Green;
timer = new Timer();
timer.Interval = 200;
timer.Tick += timer_Tick;
lblScore.Text = "0";
try
{
whiteChecker = Image.FromFile(@"images/whiteChecker.png");
redChecker = Image.FromFile(@"images/redChecker.png");
}
catch (System.Exception e)
{
MessageBox.Show("Failed to load King checker images", "Error");
gameOver = true;
}
}
private List<Move> GetMoves(Player.PlayerColor playerColor)
{
PrepareBitBoards();
var moves = new List<Move>();
for (Byte index = 0; index < _board.Length; index++)
{
Player.PlayerColor currentSquareCheckerColor = Player.GetCheckerColor((Piece)_board[index]);
if (currentSquareCheckerColor == playerColor)
{
switch ((Piece)_board[index])
{
case Piece.WhiteKing:
case Piece.RedKing:
if (CanMoveNW(index))
{
Byte endSquare = GetSquareFromBitboard(whiteAttackSquares[index][0]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
if (CanMoveNE(index))
{
Byte endSquare = GetSquareFromBitboard(whiteAttackSquares[index][1]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
if (CanMoveSW(index))
{
Byte endSquare = GetSquareFromBitboard(redAttackSquares[index][0]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
if (CanMoveSE(index))
{
Byte endSquare = GetSquareFromBitboard(redAttackSquares[index][1]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
break;
case Piece.WhiteChecker:
if (CanMoveNW(index))
{
Byte endSquare = GetSquareFromBitboard(whiteAttackSquares[index][0]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
if (CanMoveNE(index))
{
Byte endSquare = GetSquareFromBitboard(whiteAttackSquares[index][1]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
break;
case Piece.RedChecker:
if (CanMoveSW(index))
{
Byte endSquare = GetSquareFromBitboard(redAttackSquares[index][0]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
if (CanMoveSE(index))
{
Byte endSquare = GetSquareFromBitboard(redAttackSquares[index][1]);
var move = new Move(index, endSquare, false) { WillKing = IsKingingSquare(endSquare) };
moves.Add(move);
}
break;
}
}
}
return moves;
}
public Move GetMove(Byte[] board, Player player)
{
_board = board;
var savedPlayerColor = player.Color;
var move = (mustJumpFromSquare == 0) ? DoAI(player) : GetJumpFromChoices(player);
player.SetColor(savedPlayerColor);
return move;
}
private List<Move> GetPlayerLegalMoves(Player player)
{
String playerColor = player.Color.ToString().ToLower();
List<Move> moves = _engine.FindMoves(_board, playerColor);
return moves;
}
private Int32 negamax(List<Move> moves, Int32 plies, Player player)
{
if (plies == 0 || moves.Count == 0)
return EvaluateBoard(null);
Int32 best = Int32.MinValue;
Int32 current;
foreach (var m in moves)
{
_history.Push((Byte[])_board.Clone());
MakeMove(m);
ChangeSides(player);
var nextMoves = GetPlayerLegalMoves(player);
current = -(negamax(nextMoves, plies - 1, player));
ChangeSides(player);
if (current > best)
best = current;
_board = _history.Pop();
}
return best;
}
private Move GetJumpFromChoices(Player player)
{
Move move = null;
if (jumpChoices.Count() == 1)
{
move = jumpChoices[0];
DoMustJumpLogic(move);
}
else if (jumpChoices.Count() > 1)
{
move = DoAI(player, jumpChoices);
}
return move;
}
private Move DoAI(Player player, List<Move> movePool)
{
List<Move> potentialMoves = (movePool == null) ? GetPlayerLegalMoves(player) : movePool;
// no moves, game's over
if (potentialMoves.Count == 0)
return null;
// one move, must take it
if (potentialMoves.Count == 1)
{
DoMustJumpLogic(potentialMoves[0]);
return potentialMoves[0];
}
Move bestMove = potentialMoves[0];
//_evaluated = 0; // Statistics only
for (var i = 0; i < potentialMoves.Count(); i++)
{
_history.Push((Byte[])_board.Clone());
MakeMove(potentialMoves[i]);
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
var moves = GetPlayerLegalMoves(player);
//potentialMoves[i].SetScore(negamax(moves, 6, player));
//potentialMoves[i].SetScore(minimax(moves, 6, player));
potentialMoves[i].SetScore(alphabeta(moves, 6, player, Int32.MinValue, Int32.MaxValue));
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
if (potentialMoves[i].Score > bestMove.Score)
bestMove = potentialMoves[i];
_board = (Byte[])_history.Pop();
}
if (bestMove != null)
DoMustJumpLogic(bestMove);
score = bestMove.Score;
return bestMove;
}
private Move DoAI(Player player)
{
return DoAI(player, null);
}
private Int32 alphabeta(List<Move> moves, Int32 plies, Player player, Int32 alpha, Int32 beta)
{
if (moves.Count == 0)
{
if (player.Color == Player.PlayerColor.WHITE)
return Int32.MaxValue;
else
return Int32.MinValue;
}
if (plies == 0)
return EvaluateBoard(null);
Int32 best = Int32.MinValue;
Int32 current;
Int32 localAlpha = alpha;
foreach (var m in moves)
{
_history.Push((Byte[])_board.Clone());
MakeMove(m);
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
var nextMoves = GetPlayerLegalMoves(player);
current = -(alphabeta(nextMoves, plies - 1, player, -beta, -localAlpha));
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
_board = _history.Pop();
if (current > best)
best = current;
if (best >= beta)
break;
if (best > localAlpha)
localAlpha = best;
}
return best;
}
private static void ChangeSides(Player player)
{
player.SetColor((player.Color == Player.PlayerColor.RED) ? Player.PlayerColor.WHITE : Player.PlayerColor.RED);
}
