public Move MiniMaxRoot(int depth, bool isMaximisingPlayer)
{
CellColor color = (CellColor)aiColor;
if (!isMaximisingPlayer)
{
color = (CellColor)opponentColor;
}
List <Move> newGameMoves = grid.GetAvailableMoves(color);
int bestMove = int.MinValue + 1;
List <Move> bestMovesFound = new List <Move>();
// loop on all moves available on this board
for (int i = 0; i < newGameMoves.Count; i++)
{
Move move = newGameMoves[i];
positionCount++;
grid.DoMove(move);
int value = -EvaluateGrid(evaluationData, depth);
if (!IsGameEnded(value))
{
// get loop on all moves available on board with this move
value = MiniMax(depth - 1, int.MinValue + 1, int.MaxValue - 1, !isMaximisingPlayer);
}
grid.UndoMove(move);
// is this move better
if (value > bestMove)
{
bestMove = value;
bestMovesFound.Clear();
bestMovesFound.Add(move);
}
else if (value == bestMove)
{
bestMovesFound.Add(move);
}
}
return(bestMovesFound[Random.Range(0, bestMovesFound.Count - 1)]);
}
public IEnumerator GetBestMove(OptimizedGrid optiGrid, System.Action <Move> toDo)
{
grid = optiGrid;
positionCount = 0;
timeSpent = 0;
float actualTime = Time.realtimeSinceStartup;
Move bestMove = new Move();
bool done = false;
yield return(new WaitForEndOfFrame());
List <Vector2> canWinCells = new List <Vector2>();
// if AI has a 4-0 pattern
if (grid.CanColorWin(aiColor, out canWinCells))
{
// if AI can move to win
if (grid.CanColorMoveToWin(aiColor, canWinCells, out bestMove))
{
grid.DoMove(bestMove);
if (IsScoreEnoughToWin(aiColor, canWinCells))
{
done = true;
}
grid.UndoMove(bestMove);
}
}
// if Player can win next turn
if (grid.CanColorWin(opponentColor, out canWinCells) && IsScoreEnoughToWin(opponentColor, canWinCells) && !done)
{
// if player can move to win next turn
if (grid.CanColorMoveToWin(opponentColor, canWinCells, out bestMove))
{
grid.DoMove(bestMove);
bool canPlayerWin = IsScoreEnoughToWin(opponentColor, canWinCells);
grid.UndoMove(bestMove);
// can AI def it ???
if (canPlayerWin && grid.CanColorMoveToWin(aiColor, canWinCells, out bestMove))
{
grid.DoMove(bestMove);
if (IsScoreEnoughToWin(aiColor, canWinCells))
{
done = true;
}
grid.UndoMove(bestMove);
}
}
}
if (!done)
{
int depth = 3;
bestMove = MiniMaxRoot(depth, true);
}
float newTime = Time.realtimeSinceStartup;
timeSpent = newTime - actualTime;
Debug.Log(positionCount + " in " + timeSpent);
toDo(bestMove);
}