private int Negamax(Vector2Int cell, int depth, bool white)
{
if (depth == 0 || (boardData.IsCellOccupied(FigureType.King, cell) &&
boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
return(Evaluate(boardData.GetFigureType(cell), cell));
}
int evaluation = int.MinValue;
Vector2Int[] whitePieces = boardData.GetAllChessPiecesByColor(white);
foreach (Vector2Int piece in whitePieces)
{
FigureType type = boardData.GetFigureType(piece);
Vector2Int[] possibleMoves = boardData.GetPossibleMoves(type, piece, white);
foreach (Vector2Int position in possibleMoves)
{
int i = -Negamax(position, depth - 1, !white);
if (i > evaluation)
{
evaluation = i;
trueMove.from = piece;
trueMove.to = position;
}
}
}
return(evaluation);
}
private GameObject GetFigureToSpawn(int c, int r)
{
Vector2Int pos = new Vector2Int(c, r);
FigureType figureType = boardData.GetFigureType(pos);
switch (figureType)
{
case FigureType.Pawn:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.pawn : blackFigurePrefabs.pawn);
case FigureType.Rook:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.rook : blackFigurePrefabs.rook);
case FigureType.Knight:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.knight : blackFigurePrefabs.knight);
case FigureType.Bishop:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.bishop : blackFigurePrefabs.bishop);
case FigureType.Queen:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.queen : blackFigurePrefabs.queen);
case FigureType.King:
return(boardData.IsCellOccupied(FigureType.White, pos) ? whiteFigurePrefabs.king : blackFigurePrefabs.king);
}
return(null);
}
//TODO: Rewrite for better reading/understanding
public void CalculateNextMove(bool white = false)
{
Vector2Int[] gamePieces = boardData.GetAllChessPiecesByColor(white);
int index = white ? -int.MaxValue : int.MaxValue;
foreach (Vector2Int cell in gamePieces)
{
figureType = boardData.GetFigureType(cell);
int i = AlphaBetaPruning(cell, difficulty, -int.MaxValue, int.MaxValue, white);
if (white)
{
if (i > index)
{
index = i;
figureToMove = cell;
bestMove = tempBestMove;
}
}
else
{
if (i < index)
{
index = i;
figureToMove = cell;
bestMove = tempBestMove;
}
}
}
}
public void HighlightPossibleMoves(Vector2Int pos)
{
UnhighlightPreviousMoves();
FigureType figureType = boardData.GetFigureType(pos.x, pos.y);
savedPossibleMoves = boardData.GetPossibleMoves(figureType, pos.x, pos.y);
for (int i = 0; i < savedPossibleMoves.Length; i++)
{
HighlightCell(savedPossibleMoves[i]);
}
}
public int GetCellValue(FigureType figureType, Vector2Int cell, bool white = true)
{
int value = 0;
switch (figureType)
{
case FigureType.Pawn:
value = white ? pawnBoardValues[cell.y * boardSize + cell.x] : pawnBoardMirroredValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
case FigureType.Rook:
value = white ? rookBoardValues[cell.y * boardSize + cell.x] : rookBoardMirroredValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
case FigureType.Knight:
value = white ? knightBoardValues[cell.y * boardSize + cell.x] : knightBoardMirroredValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
case FigureType.Bishop:
value = white ? bishopBoardValues[cell.y * boardSize + cell.x] : bishopBoardMirroredValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
case FigureType.Queen:
value = white ? queenBoardValues[cell.y * boardSize + cell.x] : queenBoardMirroredValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
case FigureType.King:
value = white ? kingBoardMiddleGameValues[cell.y * boardSize + cell.x] : kingBoardMirroredMiddleGameValues[cell.y * boardSize + cell.x];
if (boardData.IsCellOccupied(boardData.GetFigureType(cell), cell) && (boardData.IsCellOccupied(white ? FigureType.Black : FigureType.White, cell)))
{
value += GetFigureValue(figureType, white);
}
break;
default:
Debug.Log("Illegal call to GetCellValue with " + figureType + ". You can call this only on figures.");
break;
}
return(value);
}
