public function castle(King $king, Rook $rook, $kingX, $rookX)
{
unset($this->pieces[$king->getSquareKey()]);
unset($this->pieces[$rook->getSquareKey()]);
$king->setX($kingX);
$rook->setX($rookX);
$this->pieces[$king->getSquareKey()] = $king;
$this->pieces[$rook->getSquareKey()] = $rook;
}
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;
}
