public Board.move FindBestMove(char[,] board, char player)
{
List <Board.move> bestMoveList = new List <Board.move>();
Board.move bestMove = new Board.move();
bestMove.score = -100;
for (ushort x = 0; x < 3; x++)
{
for (ushort y = 0; y < 3; y++)
{
if (board[x, y] == Board.emptyPosition)
{
char[,] scenarioBoard = Board.MirorBoard(board);
scenarioBoard[x, y] = player;
Board.move someMove = new Board.move();
someMove.depth = 0;
someMove.x = x;
someMove.y = y;
someMove.score = Minimax(scenarioBoard, 0, Board.OppositePlayer(player), x, y);
if (someMove.score > bestMove.score)
{
bestMove.x = x;
bestMove.y = y;
bestMove.score = someMove.score;
}
ttt.VirtualPrint("[Evaluating] move (" + x + "," + y + ") with score: " + someMove.score);
}
}
}
ttt.VirtualPrint("[Selecting] move: (" + bestMove.x + "," + bestMove.y + ") score " + bestMove.score);
ttt.VirtualPrint("--------------------------------------");
// TODO: select random of equal score moves once working properly
return(bestMove);
}
public int Minimax(char[,] board, ushort depth, char player, ushort x, ushort y)
{
string encodedBoard = Board.Encode(board);
if (Board.TerminalState(board, player, x, y))
{
int score = GetBoardScore(board, depth, player, x, y);
return(score);
}
Board.move bestMove = new Board.move();
bestMove.depth = depth;
depth += 1;
if (player == maximizingPlayer) // maximize
{
bestMove.score = -100;
for (ushort xIndex = 0; xIndex < 3; xIndex++)
{
for (ushort yIndex = 0; yIndex < 3; yIndex++)
{
if (board[xIndex, yIndex] == Board.emptyPosition)
{
char[,] subBoard = Board.MirorBoard(board);
subBoard[xIndex, yIndex] = Board.OppositePlayer(player);
string subEncoded = Board.Encode(subBoard);
int score = Minimax(subBoard, depth, Board.OppositePlayer(player), xIndex, yIndex);
if (score > bestMove.score)
{
bestMove.score = score;
bestMove.x = xIndex;
bestMove.y = yIndex;
}
}
}
}
}
else // minimize
{
bestMove.score = 100;
for (ushort xIndex = 0; xIndex < 3; xIndex++)
{
for (ushort yIndex = 0; yIndex < 3; yIndex++)
{
if (board[xIndex, yIndex] == Board.emptyPosition)
{
char[,] subBoard = Board.MirorBoard(board);
subBoard[xIndex, yIndex] = Board.OppositePlayer(player);
string subEncoded = Board.Encode(subBoard);
int score = Minimax(subBoard, depth, Board.OppositePlayer(player), xIndex, yIndex);
if (score < bestMove.score)
{
bestMove.score = score;
bestMove.x = xIndex;
bestMove.y = yIndex;
}
}
}
}
}
return(bestMove.score);
}
// Update is called once per frame
void Update()
{
if (currentPlayer != '_') // game is waiting
{
if (currentPlayer == computer)
{
Board.move nextMove = minmax.FindBestMove(gameBoard, currentPlayer);
gameBoard[nextMove.x, nextMove.y] = currentPlayer;
peices.Add(Instantiate(oPeice, transform));
peices[peices.Count - 1].transform.position =
physicalBoard[nextMove.x, nextMove.y].transform.position + new Vector3(0, 5, -2);
if (Board.TerminalState(gameBoard, currentPlayer, nextMove.x, nextMove.y))
{
if (Board.GetWinner(gameBoard, currentPlayer, nextMove.x, nextMove.x) == computer)
{
VirtualPrint("The winner is the human");
}
else
{
VirtualPrint("The winner is nobody");
}
currentPlayer = Board.emptyPosition;
}
else
{
currentPlayer = Board.OppositePlayer(currentPlayer);
}
//VirtualPrint(Board.Visualize(gameBoard));
}
else if (Input.GetMouseButtonDown(0))
{
RaycastHit hit;
Ray ray = playerCamera.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit))
{
for (ushort x = 0; x < 3; x++)
{
for (ushort y = 0; y < 3; y++)
{
if (physicalBoard[x, y] == hit.transform.gameObject)
{
moveX = x;
moveY = y;
break;
}
}
}
}
if (Board.IsValidMove(gameBoard, currentPlayer, moveX, moveY))
{
peices.Add(Instantiate(xPeice, transform));
peices[peices.Count - 1].transform.position =
physicalBoard[moveX, moveY].transform.position + new Vector3(0, 5, 0);
gameBoard[moveX, moveY] = currentPlayer;
if (Board.TerminalState(gameBoard, currentPlayer, moveX, moveY))
{
if (Board.GetWinner(gameBoard, currentPlayer, moveX, moveY) == human)
{
VirtualPrint("The winner is the human");
}
else
{
VirtualPrint("The winner is nobody");
}
currentPlayer = Board.emptyPosition;
}
else
{
currentPlayer = Board.OppositePlayer(currentPlayer);
}
//VirtualPrint(Board.Visualize(gameBoard));
}
}
}
if (Input.GetMouseButtonDown(0))
{
RaycastHit hit;
Ray ray = playerCamera.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit))
{
if (reset == hit.transform.gameObject)
{
StartNewGame();
moveX = 5;
}
}
}
}
