private int Evaluate(HexAIMove move, Game game)
{
int score = random.Next(0, 25); // avoid making every run the same
var state = game.GetCurrentBoardState();
Team ourTeam = state.currentMove;
Team enemy = ourTeam.Enemy();
(BoardState newState, List <Promotion> newPromotions) = move.Speculate(game);
bool weAreChecking = MoveValidator.IsChecking(ourTeam, newState, newPromotions);
bool enemyHasMoves = MoveValidator.HasAnyValidMoves(enemy, newPromotions, newState, state);
if (weAreChecking && !enemyHasMoves)
{
return(int.MaxValue);
}
if (weAreChecking)
{
score += CheckBonus;
}
if (!enemyHasMoves)
{
score -= StalematePenalty;
}
if (move.moveType == MoveType.Attack)
{
var attacker = HexachessagonEngine.GetRealPiece(move.start, state, game.promotions);
var victim = HexachessagonEngine.GetRealPiece(move.target, state, game.promotions);
score += AttackBonus;
score += GetPieceValue(victim) - GetPieceValue(attacker);
}
else if (move.moveType == MoveType.EnPassant)
{
score += EnPassantBonus;
}
else if (move.moveType == MoveType.Move)
{
var mover = state.allPiecePositions[move.start];
if (mover.piece.IsPawn())
{
int ranksForward = move.target.GetNumber() - move.start.GetNumber();
if (ourTeam == Team.Black)
{
ranksForward = -ranksForward;
}
ranksForward *= 5;
score *= ranksForward;
}
}
else
{
// Defend is pretty worthless for a bloodthirsty AI
score -= 10;
}
return(score);
}
