protected function isCastleKingSide(King $king, Square $to) { if ($to->getPiece()) { return $to->getX() > $king->getX(); } else { return 7 === $to->getX(); } }
/** * Add castling moves if available * * @return array the squares where the king can go **/ protected function addCastlingSquares(King $king, array $squares) { $player = $king->getPlayer(); $rooks = PieceFilter::filterNotMoved(PieceFilter::filterClass(PieceFilter::filterAlive($player->getPieces()), 'Rook')); if (empty($rooks)) { return $squares; } $opponentControlledKeys = $this->getPlayerControlledKeys($player->getOpponent(), true); foreach ($rooks as $rook) { $kingX = $king->getX(); $kingY = $king->getY(); $rookX = $rook->getX(); $dx = $kingX > $rookX ? -1 : 1; $newKingX = 1 === $dx ? 7 : 3; $newRookX = 1 === $dx ? 6 : 4; $possible = true; // Unattacked $rangeMin = min($kingX, $newKingX); $rangeMax = min(8, max($kingX, $newKingX) + 1); for ($_x = $rangeMin; $_x !== $rangeMax; $_x++) { if (in_array(Board::posToKey($_x, $kingY), $opponentControlledKeys)) { $possible = false; break; } } // Unimpeded $rangeMin = min($kingX, $rookX, $newKingX, $newRookX); $rangeMax = min(8, max($kingX, $rookX, $newKingX, $newRookX) + 1); for ($_x = $rangeMin; $_x !== $rangeMax; $_x++) { if ($piece = $this->board->getPieceByKey(Board::posToKey($_x, $kingY))) { if ($piece !== $king && $piece !== $rook) { $possible = false; break; } } } if ($possible) { // If King moves one square or less (Chess variant) if (1 >= abs($kingX - $newKingX)) { $newKingSquare = $rook->getSquare(); } else { $newKingSquare = $this->board->getSquareByPos($newKingX, $kingY); } $squares[] = $newKingSquare; } } return $squares; }