private void MakeMove()
{
if (_moves.Count <= 1) ResetMove();
else
{
var pos = new BoardPosition[_moves.Count];
_moves.CopyTo(0, pos, 0, _moves.Count);
bool eatMove = CheckersMove.IsEatMove(this.MyBoard, pos);
var move = new CheckersMove(pos, eatMove);
_lastMoveOk = true;
((HumanCheckersPlayer)CurrentPlayer).MakeAMove(move);
if (_lastMoveOk) _lastMove = move;
else _lastMove = null;
CheckStatus();
ResetMove();
}
}
bool IsPrefix(List<BoardPosition> path, CheckersMove move)
{
if (path.Count > move.MovePath.Length)
return false;
for (int i = 0; i < path.Count; i++)
if (path[i].X != move.MovePath[i].X || path[i].Y != move.MovePath[i].Y)
return false;
return true;
}
protected double SelectMove(CheckersBoard board, PieceColor color, int currentSearchDepth, double alpha, double beta)
{
var moves=board.RightMoves(color);
if(currentSearchDepth==0 || moves.Count==0)
return _boardEvaluator.Eval(board, currentSearchDepth,Color);
else
{
//if have only one oportunnity the return this one and save time
if (currentSearchDepth == MaxSearchDepth && (moves.Count == 1)) {
selectedMove = moves[0];
return 0;
}
double max=(this.Color==color)? double.MinValue: double.MaxValue;
for(int i=0;i<moves.Count;i++)
{
var move = moves[i];
CheckersBoard newBoard=PerformMove(board, move);
double eval=SelectMove(newBoard, color == PieceColor.White ? PieceColor.Black : PieceColor.White, currentSearchDepth-1,alpha,beta);
if(color==this.Color) {
if(max<eval)
{
max=eval;
if(currentSearchDepth==MaxSearchDepth)
{
selectedMove=move;
//System.Windows.Forms.MessageBox.Show("Got a move "+selectedMove + " currentSearchDepth :"+MaxSearchDepth);
}
if (beta<=max) break;
else alpha = Math.Max(alpha,max);
}
else if(max==eval)
{
if((currentSearchDepth==MaxSearchDepth) && (r.Next(9)%2==0))
{
selectedMove=move;
//System.Windows.Forms.MessageBox.Show("Got a move "+selectedMove + " currentSearchDepth :"+MaxSearchDepth);
}
}
}
else {
if(max>eval) max=eval;
if (alpha>=max) break;
else beta = Math.Min(beta,max);
}
//System.Windows.Forms.MessageBox.Show(newBoard.ToString()+'\n'+"Level "+currentSearchDepth+" Color "+color+" Max "+max+" eval "+eval);
}
return max;
}
}
public void MakeAMove(CheckersMove move)
{
if (OnPerformMove!=null) OnPerformMove(this,move);
}
protected CheckersBoard PerformMove(CheckersBoard board, CheckersMove move)
{
CheckersBoard newBoard=(CheckersBoard)board.Clone();
int x1=move.MovePath[0].X;
int y1=move.MovePath[0].Y;
CheckersPiece movingPiece=(CheckersPiece)newBoard.GetPieceAt(x1, y1);
for(int i=0; i<move.MovePath.Length-1; i++)
{
int x2=move.MovePath[i+1].X;
int y2=move.MovePath[i+1].Y;
int incX=Inc(x1, x2);
int incY=Inc(y1, y2);
while(x1!=x2 || y1!=y2)
{
CheckersPiece piece=newBoard.GetPieceAt(x1, y1) as CheckersPiece;
if(piece!=null)
{
newBoard.RemovePiece(piece);
}
x1+=incX;
y1+=incY;
}
}
//White queen
if(y1==0 && movingPiece.Color==PieceColor.White)
{
newBoard.PutPieceAt(x1, y1, new Queen(newBoard, x1, y1, PieceColor.White));
}
else if(y1==7 && movingPiece.Color==PieceColor.Black) //black queen
{
newBoard.PutPieceAt(x1, y1, new Queen(newBoard, x1, y1, PieceColor.Black));
}
else //simply move piece
newBoard.PutPieceAt(x1, y1, movingPiece);
return newBoard;
}
