mambax7 / chess

class/chessgame.inc.php

Indentation +581 added lines, -581 removed lines

@@ -53,34 +53,34 @@ 
 class ChessGame {
 
 	/**
-    * Indicates whether object is valid.
-    *
-    * If empty string (''), indicates this is a valid object; otherwise contains an error message.
+	 * Indicates whether object is valid.
+	 *
+	 * If empty string (''), indicates this is a valid object; otherwise contains an error message.
 	 * Should be checked after creating an instance of this class.
-    *
-    * @var string $error
-    */
+	 *
+	 * @var string $error
+	 */
 	var $error;
 
    /**
     * gamestate
     *
-	 * The game state is represented as an array with the following elements:
-	 *
-	 *  - 'fen_piece_placement'
-	 *  - 'fen_active_color'
-	 *  - 'fen_castling_availability'
-	 *  - 'fen_en_passant_target_square'
-	 *  - 'fen_halfmove_clock'
-	 *  - 'fen_fullmove_number'
-	 *  - 'pgn_result'
-	 *  - 'pgn_fen'
-	 *  - 'pgn_movetext'
-	 *
-	 * The elements prefixed with 'fen_' are standard Forsyth-Edwards Notation (FEN) elements,
-	 * and the elements prefixed with 'pgn_' are standard Portable Game Notation (PGN) elements.
-	 *
-	 * Each element is a string.
+    * The game state is represented as an array with the following elements:
+    *
+    *  - 'fen_piece_placement'
+    *  - 'fen_active_color'
+    *  - 'fen_castling_availability'
+    *  - 'fen_en_passant_target_square'
+    *  - 'fen_halfmove_clock'
+    *  - 'fen_fullmove_number'
+    *  - 'pgn_result'
+    *  - 'pgn_fen'
+    *  - 'pgn_movetext'
+    *
+    * The elements prefixed with 'fen_' are standard Forsyth-Edwards Notation (FEN) elements,
+    * and the elements prefixed with 'pgn_' are standard Portable Game Notation (PGN) elements.
+    *
+    * Each element is a string.
     *
     * @var array $gamestate
     */
@@ -89,23 +89,23 @@ 
    /**
     * board
     *
-	 * A 64-element array, constructed from fen_piece_placement, is used for handling moves.
-	 * Its indices are related to the standard tile coordinates as follows:
-	 *
+    * A 64-element array, constructed from fen_piece_placement, is used for handling moves.
+    * Its indices are related to the standard tile coordinates as follows:
+    *
     * <pre>
-	 * 8 | 56 57 58 59 60 61 62 63
-	 * 7 | 48 49 50 51 52 53 54 55
-	 * 6 | 40 41 42 43 44 45 46 47
-	 * 5 | 32 33 34 35 36 37 38 39
-	 * 4 | 24 25 26 27 28 29 30 31
-	 * 3 | 16 17 18 19 20 21 22 23
-	 * 2 |  8  9 10 11 12 13 14 15
-	 * 1 |  0  1  2  3  4  5  6  7
-	 *    ------------------------
-	 *      a  b  c  d  e  f  g  h
+    * 8 | 56 57 58 59 60 61 62 63
+    * 7 | 48 49 50 51 52 53 54 55
+    * 6 | 40 41 42 43 44 45 46 47
+    * 5 | 32 33 34 35 36 37 38 39
+    * 4 | 24 25 26 27 28 29 30 31
+    * 3 | 16 17 18 19 20 21 22 23
+    * 2 |  8  9 10 11 12 13 14 15
+    * 1 |  0  1  2  3  4  5  6  7
+    *    ------------------------
+    *      a  b  c  d  e  f  g  h
     * </pre>
-	 *
-	 * For example, $board[17] is tile b3 and $board[55] is tile h7.
+    *
+    * For example, $board[17] is tile b3 and $board[55] is tile h7.
     *
     * @var array $board
     */
@@ -131,13 +131,13 @@ 
 
 
    /**
-	 * updated by handleMove, not used now but might be used in future
+    * updated by handleMove, not used now but might be used in future
     * @var string $last_move
     */
 	var $last_move;
 
    /**
-	 * updated by handleMove, not used now but might be used in future
+    * updated by handleMove, not used now but might be used in future
     * @var string $captured_piece
     */
 	var $captured_piece;
@@ -455,65 +455,65 @@ 
   /* DEBUG:  echo "$fx,$fy --> $dx,$dy: "; */
   switch ( $fig )
   {
-    /* knight */
-    case 'N':
-      if ( abs($fx-$dx)==1 && abs($fy-$dy)==2 )
-        $result = 1;
-      if ( abs($fy-$dy)==1 && abs($fx-$dx)==2 )
-        $result = 1;
-      break;
-    /* bishop */
-    case 'B':
-      if ( abs($fx-$dx) != abs($fy-$dy) )
-        break;
-      if ( $dy < $fy ) $change = -8; else $change =  8;
-      if ( $dx < $fx ) $change -= 1; else $change += 1;
-      if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
-        $result = 1;
-      break;
-    /* rook */
-    case 'R':
-      if ( $fx!=$dx && $fy!=$dy )
-        break;
-      if ( $fx==$dx ) 
-      {
-        if ( $dy<$fy ) $change = -8; else $change = 8;
-      }
-      else {
-        if ( $dx<$fx ) $change = -1; else $change = 1;
-      }
-      if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
-        $result = 1;
-      break;
-    /* queen */
-    case 'Q':
-      if ( abs($fx-$dx) != abs($fy-$dy) && $fx!=$dx && $fy!=$dy )
-        break;
-      if ( abs($fx-$dx) == abs($fy-$dy) )
-      {
-        if ( $dy < $fy ) $change = -8; else $change =  8;
-        if ( $dx < $fx ) $change -= 1; else $change += 1;
-      }
-      else if ( $fx==$dx ) {
-        if ( $dy<$fy ) $change = -8; else $change = 8;
-      } 
-      else
-      {
-        if ( $dx<$fx ) $change = -1; else $change = 1;
-      }
-      if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
-        $result = 1;
-      break;
-    /* king */
-    case 'K':
-      if ( abs($fx-$dx) > 1 || abs($fy-$dy) > 1 ) break;
-      $kings = 0;
-      $adj_tiles = $this->getAdjTiles( $dest_pos );
-      foreach( $adj_tiles as $tile )
-        if ($this->board[$tile]{1} == 'K' ) $kings++;
-      if ( $kings == 2 ) break;
-      $result = 1;
-      break;
+	/* knight */
+	case 'N':
+	  if ( abs($fx-$dx)==1 && abs($fy-$dy)==2 )
+		$result = 1;
+	  if ( abs($fy-$dy)==1 && abs($fx-$dx)==2 )
+		$result = 1;
+	  break;
+	/* bishop */
+	case 'B':
+	  if ( abs($fx-$dx) != abs($fy-$dy) )
+		break;
+	  if ( $dy < $fy ) $change = -8; else $change =  8;
+	  if ( $dx < $fx ) $change -= 1; else $change += 1;
+	  if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
+		$result = 1;
+	  break;
+	/* rook */
+	case 'R':
+	  if ( $fx!=$dx && $fy!=$dy )
+		break;
+	  if ( $fx==$dx ) 
+	  {
+		if ( $dy<$fy ) $change = -8; else $change = 8;
+	  }
+	  else {
+		if ( $dx<$fx ) $change = -1; else $change = 1;
+	  }
+	  if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
+		$result = 1;
+	  break;
+	/* queen */
+	case 'Q':
+	  if ( abs($fx-$dx) != abs($fy-$dy) && $fx!=$dx && $fy!=$dy )
+		break;
+	  if ( abs($fx-$dx) == abs($fy-$dy) )
+	  {
+		if ( $dy < $fy ) $change = -8; else $change =  8;
+		if ( $dx < $fx ) $change -= 1; else $change += 1;
+	  }
+	  else if ( $fx==$dx ) {
+		if ( $dy<$fy ) $change = -8; else $change = 8;
+	  } 
+	  else
+	  {
+		if ( $dx<$fx ) $change = -1; else $change = 1;
+	  }
+	  if ( $this->pathIsNotBlocked( $fig_pos+$change, $dest_pos, $change ) )
+		$result = 1;
+	  break;
+	/* king */
+	case 'K':
+	  if ( abs($fx-$dx) > 1 || abs($fy-$dy) > 1 ) break;
+	  $kings = 0;
+	  $adj_tiles = $this->getAdjTiles( $dest_pos );
+	  foreach( $adj_tiles as $tile )
+		if ($this->board[$tile]{1} == 'K' ) $kings++;
+	  if ( $kings == 2 ) break;
+	  $result = 1;
+	  break;
   }
 
   /* DEBUG: echo " $result<BR>"; */
@@ -533,17 +533,17 @@ 
 {
   if ( $this->board[$fig_pos]{0} == 'w' )
   {
-    if ( ($fig_pos % 8) > 0 && $dest_pos == $fig_pos+7 )
-      return 1;
-    if ( ($fig_pos % 8) < 7 && $dest_pos == $fig_pos+9 )
-      return 1;
+	if ( ($fig_pos % 8) > 0 && $dest_pos == $fig_pos+7 )
+	  return 1;
+	if ( ($fig_pos % 8) < 7 && $dest_pos == $fig_pos+9 )
+	  return 1;
   }
   else if ( $this->board[$fig_pos]{0} == 'b' )
   {
-    if ( ($fig_pos % 8) < 7 && $dest_pos == $fig_pos-7 )
-      return 1;
-    if ( ($fig_pos % 8) > 0 && $dest_pos == $fig_pos-9 )
-      return 1;
+	if ( ($fig_pos % 8) < 7 && $dest_pos == $fig_pos-7 )
+	  return 1;
+	if ( ($fig_pos % 8) > 0 && $dest_pos == $fig_pos-9 )
+	  return 1;
   }
   return 0;
 }
@@ -568,23 +568,23 @@ 
   
   if ( $this->board[$fig_pos]{0} == 'w' )
   {
-    if ( $fig_pos >= 8 && $fig_pos <= 15 )
-      $first_move = 1;
-    if ( $dest_pos==$fig_pos+8 )
-      return 1;
-    if ( $first_move && ( $dest_pos==$fig_pos+16 ) )
-    if ($this->is_empty_tile($fig_pos + 8))
-      return 1;
+	if ( $fig_pos >= 8 && $fig_pos <= 15 )
+	  $first_move = 1;
+	if ( $dest_pos==$fig_pos+8 )
+	  return 1;
+	if ( $first_move && ( $dest_pos==$fig_pos+16 ) )
+	if ($this->is_empty_tile($fig_pos + 8))
+	  return 1;
   }
   else if ($this->board[$fig_pos]{0} == 'b' )
   {
-    if ( $fig_pos >= 48 && $fig_pos <= 55 )
-      $first_move = 1;
-    if ( $dest_pos==$fig_pos-8 )
-      return 1;
-    if ( $first_move && ( $dest_pos==$fig_pos-16 ) )
-    if ($this->is_empty_tile($fig_pos - 8))
-      return 1;
+	if ( $fig_pos >= 48 && $fig_pos <= 55 )
+	  $first_move = 1;
+	if ( $dest_pos==$fig_pos-8 )
+	  return 1;
+	if ( $first_move && ( $dest_pos==$fig_pos-16 ) )
+	if ($this->is_empty_tile($fig_pos - 8))
+	  return 1;
   }
   return 0;
 }
@@ -602,16 +602,16 @@ 
 {
 #var_dump('tileIsUnderAttack, opp', $opp, 'dest_pos', $dest_pos, 'board', $board);#*#DEBUG#
   for ( $i = 0; $i < 64; $i++ )
-    if ($this->board[$i]{0} == $opp )
-    {
-      if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$dest_pos)) ||
-           ($this->board[$i]{1}!='P' && 
-                $this->tileIsReachable($this->board[$i]{1},$i,$dest_pos)) )
-      {
-        /*DEBUG: echo "attack test: $i: ",$opp,"P<BR>"; */
-        return 1;
-      }
-    }
+	if ($this->board[$i]{0} == $opp )
+	{
+	  if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$dest_pos)) ||
+		   ($this->board[$i]{1}!='P' && 
+				$this->tileIsReachable($this->board[$i]{1},$i,$dest_pos)) )
+	  {
+		/*DEBUG: echo "attack test: $i: ",$opp,"P<BR>"; */
+		return 1;
+	  }
+	}
   return 0;
 }
 
@@ -629,11 +629,11 @@ 
 
 #var_dump('kingIsUnderAttack, player', $player, 'opp', $opp, 'board', $board);#*#DEBUG#
   for ( $i = 0; $i < 64; $i++ )
-    if ($this->board[$i]{0} == $player && $this->board[$i]{1} == 'K' )
-    {
-      $king_pos = $i;
-      break;
-    }
+	if ($this->board[$i]{0} == $player && $this->board[$i]{1} == 'K' )
+	{
+	  $king_pos = $i;
+	  break;
+	}
   /*DEBUG: echo "$player king is at $king_pos<BR>"; */
   
   return $this->tileIsUnderAttack( $opp, $king_pos );
@@ -651,23 +651,23 @@ 
 function isCheckMate($player, $opp)
 {
   for ( $i = 0; $i < 64; $i++ )
-    if ($this->board[$i]{0} == $player && $this->board[$i]{1} == 'K' )
-    {
-      $king_pos = $i;
-      $king_x = $i % 8;
-      $king_y = floor($i/8);
-      break;
-    }
+	if ($this->board[$i]{0} == $player && $this->board[$i]{1} == 'K' )
+	{
+	  $king_pos = $i;
+	  $king_x = $i % 8;
+	  $king_y = floor($i/8);
+	  break;
+	}
 
   /* test adjacent tiles while king is temporarly removed */
   $adj_tiles = $this->getAdjTiles( $king_pos );
   $contents = $this->board[$king_pos]; $this->clear_tile($king_pos);
   foreach ( $adj_tiles as $dest_pos ) 
   {
-    if ($this->board[$dest_pos]{0} == $player ) continue;
-    if ( $this->tileIsUnderAttack($opp,$dest_pos) ) continue;
-    $this->board[$king_pos] = $contents;
-    return 0;
+	if ($this->board[$dest_pos]{0} == $player ) continue;
+	if ( $this->tileIsUnderAttack($opp,$dest_pos) ) continue;
+	$this->board[$king_pos] = $contents;
+	return 0;
   }
   $this->board[$king_pos] = $contents;
 
@@ -676,15 +676,15 @@ 
   /* get all figures that attack the king */
   $attackers = array(); $count = 0;
   for ( $i = 0; $i < 64; $i++ )
-    if ( $this->board[$i]{0} == $opp )
-    {
-      if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$king_pos)) ||
-           ($this->board[$i]{1}!='P' && 
-                $this->tileIsReachable($this->board[$i]{1},$i,$king_pos)) )
-      {
-          $attackers[$count++] = $i;
-      }
-    }
+	if ( $this->board[$i]{0} == $opp )
+	{
+	  if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$king_pos)) ||
+		   ($this->board[$i]{1}!='P' && 
+				$this->tileIsReachable($this->board[$i]{1},$i,$king_pos)) )
+	  {
+		  $attackers[$count++] = $i;
+	  }
+	}
   /* DEBUG: 
   for( $i = 0; $i < $count; $i++ )
     echo "Attacker: $attackers[$i] ";
@@ -696,32 +696,32 @@ 
   /* check whether attacker can be killed by own figure */
   $dest_pos = $attackers[0];
   for ( $i = 0; $i < 64; $i++ )
-    if ( $this->board[$i]{0} == $player )
-    {
-      if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$dest_pos)) ||
-           ($this->board[$i]{1}!='P' && $this->board[$i]{1}!='K' &&
-              $this->tileIsReachable($this->board[$i]{1},$i,$dest_pos)) ||
-           ($this->board[$i]{1}=='K' && 
-              $this->tileIsReachable($this->board[$i]{1},$i,$dest_pos) &&
-              !$this->tileIsUnderAttack($opp,$dest_pos)) )
-      {
-        /* DEBUG: echo "candidate: $i "; */
-        $can_kill_atk = 0;
-        $contents_def = $this->board[$i];
-        $contents_atk = $this->board[$dest_pos];
-        $this->board[$dest_pos] = $this->board[$i];
-        $this->clear_tile($i);
-        if ( !$this->tileIsUnderAttack($opp,$king_pos) )
-          $can_kill_atk = 1;
-        $this->board[$i] = $contents_def;
-        $this->board[$dest_pos] = $contents_atk;
-        if ( $can_kill_atk )
-        {
-          /* DEBUG: echo "$i can kill attacker"; */
-          return 0;
-        }    
-      }
-    }
+	if ( $this->board[$i]{0} == $player )
+	{
+	  if ( ($this->board[$i]{1}=='P' && $this->checkPawnAttack($i,$dest_pos)) ||
+		   ($this->board[$i]{1}!='P' && $this->board[$i]{1}!='K' &&
+			  $this->tileIsReachable($this->board[$i]{1},$i,$dest_pos)) ||
+		   ($this->board[$i]{1}=='K' && 
+			  $this->tileIsReachable($this->board[$i]{1},$i,$dest_pos) &&
+			  !$this->tileIsUnderAttack($opp,$dest_pos)) )
+	  {
+		/* DEBUG: echo "candidate: $i "; */
+		$can_kill_atk = 0;
+		$contents_def = $this->board[$i];
+		$contents_atk = $this->board[$dest_pos];
+		$this->board[$dest_pos] = $this->board[$i];
+		$this->clear_tile($i);
+		if ( !$this->tileIsUnderAttack($opp,$king_pos) )
+		  $can_kill_atk = 1;
+		$this->board[$i] = $contents_def;
+		$this->board[$dest_pos] = $contents_atk;
+		if ( $can_kill_atk )
+		{
+		  /* DEBUG: echo "$i can kill attacker"; */
+		  return 0;
+		}    
+	  }
+	}
  
   /* check whether own unit can block the way */
   
@@ -734,7 +734,7 @@ 
   $dest_x = $dest_pos % 8;
   $dest_y = floor($dest_pos/8);
   if ( abs($dest_x-$king_x)<=1 && abs($dest_y-$king_y)<=1 )
-    return 1;
+	return 1;
 
   /* get the list of tiles between king and attacking
    * unit that can be blocked to stop the attack */
@@ -744,17 +744,17 @@ 
   /* DEBUG: foreach( $path as $tile ) echo "tile: $tile "; */
   foreach( $path as $pos )
   {
-    for ( $i = 0; $i < 64; $i++ )
-      if ( $this->board[$i]{0} == $player )
-      {
-        if ( ($this->board[$i]{1}=='P' && $this->checkPawnMove($i,$pos)) ||
-             ($this->board[$i]{1}!='P' && $this->board[$i]{1}!='K' &&
-                  $this->tileIsReachable($this->board[$i]{1},$i,$pos)) )
-        {
-            /* DEBUG: echo "$i can block "; */
-            return 0;
-        }
-      }
+	for ( $i = 0; $i < 64; $i++ )
+	  if ( $this->board[$i]{0} == $player )
+	  {
+		if ( ($this->board[$i]{1}=='P' && $this->checkPawnMove($i,$pos)) ||
+			 ($this->board[$i]{1}!='P' && $this->board[$i]{1}!='K' &&
+				  $this->tileIsReachable($this->board[$i]{1},$i,$pos)) )
+		{
+			/* DEBUG: echo "$i can block "; */
+			return 0;
+		}
+	  }
   }
   return 1;
 }
@@ -773,62 +773,62 @@ 
 function isStaleMate($player, $opp)
 {
   for ( $i = 0; $i < 64; $i++ )
-    if ($this->board[$i]{0} == $player )
-      switch ($this->board[$i]{1} )
-      {
-        case 'K':
-          $adj_tiles = $this->getAdjTiles( $i );
-          foreach ( $adj_tiles as $pos ) 
-          {
-            if ( $this->board[$pos]{0} == $player ) continue;
-            if ( $this->tileIsUnderAttack($opp,$pos) ) continue;
-            return 0;
-          }
-          /* DEBUG:  echo "King cannot escape by itself! "; */
-          break;
-        case 'P':
-          if ( $player == 'w' )
-          {
-            if ($this->is_empty_tile($i + 8)) return 0;
-            if ( ($i%8) > 0 && $this->board[$i+7]{0} != $player ) return 0;
-            if ( ($i%8) < 7 && $this->board[$i+9]{0} != $player ) return 0;
-          }
-          else
-          {
-            if ($this->is_empty_tile($i - 8)) return 0;
-            if ( ($i%8) > 0 && $this->board[$i-9]{0} != $player ) return 0;
-            if ( ($i%8) < 7 && $this->board[$i-7]{0} != $player ) return 0;
-          }
-          break;
-        case 'B':
-          if ( $i-9 >= 0  && $this->board[$i-9]{0} != $player ) return 0;
-          if ( $i-7 >= 0  && $this->board[$i-7]{0} != $player ) return 0;
-          if ( $i+9 <= 63 && $this->board[$i+9]{0} != $player ) return 0;
-          if ( $i+7 <= 63 && $this->board[$i+7]{0} != $player ) return 0;
-          break;
-        case 'R':
-          if ( $i-8 >= 0  && $this->board[$i-8]{0} != $player ) return 0;
-          if ( $i-1 >= 0  && $this->board[$i-1]{0} != $player ) return 0;
-          if ( $i+8 <= 63 && $this->board[$i+8]{0} != $player ) return 0;
-          if ( $i+1 <= 63 && $this->board[$i+1]{0} != $player ) return 0;
-          break;
-        case 'Q':
-          $adj_tiles = $this->getAdjTiles( $i );
-          foreach ( $adj_tiles as $pos )
-            if ( $this->board[$pos]{0} != $player ) 
-              return 0;
-          break;
-        case 'N':
-          if ( $i-17 >= 0  && $this->board[$i-17]{0} != $player ) return 0; 
-          if ( $i-15 >= 0  && $this->board[$i-15]{0} != $player ) return 0;
-          if ( $i-6  >= 0  && $this->board[$i-6]{0}  != $player ) return 0;
-          if ( $i+10 <= 63 && $this->board[$i+10]{0} != $player ) return 0;
-          if ( $i+17 <= 63 && $this->board[$i+17]{0} != $player ) return 0;
-          if ( $i+15 <= 63 && $this->board[$i+15]{0} != $player ) return 0;
-          if ( $i+6  <= 63 && $this->board[$i+6]{0}  != $player ) return 0;
-          if ( $i-10 >= 0  && $this->board[$i-10]{0} != $player ) return 0;
-          break;
-      }
+	if ($this->board[$i]{0} == $player )
+	  switch ($this->board[$i]{1} )
+	  {
+		case 'K':
+		  $adj_tiles = $this->getAdjTiles( $i );
+		  foreach ( $adj_tiles as $pos ) 
+		  {
+			if ( $this->board[$pos]{0} == $player ) continue;
+			if ( $this->tileIsUnderAttack($opp,$pos) ) continue;
+			return 0;
+		  }
+		  /* DEBUG:  echo "King cannot escape by itself! "; */
+		  break;
+		case 'P':
+		  if ( $player == 'w' )
+		  {
+			if ($this->is_empty_tile($i + 8)) return 0;
+			if ( ($i%8) > 0 && $this->board[$i+7]{0} != $player ) return 0;
+			if ( ($i%8) < 7 && $this->board[$i+9]{0} != $player ) return 0;
+		  }
+		  else
+		  {
+			if ($this->is_empty_tile($i - 8)) return 0;
+			if ( ($i%8) > 0 && $this->board[$i-9]{0} != $player ) return 0;
+			if ( ($i%8) < 7 && $this->board[$i-7]{0} != $player ) return 0;
+		  }
+		  break;
+		case 'B':
+		  if ( $i-9 >= 0  && $this->board[$i-9]{0} != $player ) return 0;
+		  if ( $i-7 >= 0  && $this->board[$i-7]{0} != $player ) return 0;
+		  if ( $i+9 <= 63 && $this->board[$i+9]{0} != $player ) return 0;
+		  if ( $i+7 <= 63 && $this->board[$i+7]{0} != $player ) return 0;
+		  break;
+		case 'R':
+		  if ( $i-8 >= 0  && $this->board[$i-8]{0} != $player ) return 0;
+		  if ( $i-1 >= 0  && $this->board[$i-1]{0} != $player ) return 0;
+		  if ( $i+8 <= 63 && $this->board[$i+8]{0} != $player ) return 0;
+		  if ( $i+1 <= 63 && $this->board[$i+1]{0} != $player ) return 0;
+		  break;
+		case 'Q':
+		  $adj_tiles = $this->getAdjTiles( $i );
+		  foreach ( $adj_tiles as $pos )
+			if ( $this->board[$pos]{0} != $player ) 
+			  return 0;
+		  break;
+		case 'N':
+		  if ( $i-17 >= 0  && $this->board[$i-17]{0} != $player ) return 0; 
+		  if ( $i-15 >= 0  && $this->board[$i-15]{0} != $player ) return 0;
+		  if ( $i-6  >= 0  && $this->board[$i-6]{0}  != $player ) return 0;
+		  if ( $i+10 <= 63 && $this->board[$i+10]{0} != $player ) return 0;
+		  if ( $i+17 <= 63 && $this->board[$i+17]{0} != $player ) return 0;
+		  if ( $i+15 <= 63 && $this->board[$i+15]{0} != $player ) return 0;
+		  if ( $i+6  <= 63 && $this->board[$i+6]{0}  != $player ) return 0;
+		  if ( $i-10 >= 0  && $this->board[$i-10]{0} != $player ) return 0;
+		  break;
+	  }
       
   return 1;
 }
@@ -890,12 +890,12 @@ 
 
   if ( strlen($move)>=6 ) 
   {
-    /* full move: a pawn requires a ? in the end
+	/* full move: a pawn requires a ? in the end
      * to automatically choose a queen on last line */
-    if ( $move[0] == 'P' )
-    if ( $move[strlen($move)-1]<'A' || $move[strlen($move)-1]>'Z' )
-      $this->ac_move = "$move?";
-    return "";
+	if ( $move[0] == 'P' )
+	if ( $move[strlen($move)-1]<'A' || $move[strlen($move)-1]>'Z' )
+	  $this->ac_move = "$move?";
+	return "";
   }
 
   /* allow last letter to be a capital one indicating
@@ -905,186 +905,186 @@ 
   $pawn_upg = "?";
   if ( $move[strlen($move)-1]>='A' && $move[strlen($move)-1]<='Z' )
   {
-    $pawn_upg = $move[strlen($move)-1];
-    $move = substr( $move, 0, strlen($move)-1 );
+	$pawn_upg = $move[strlen($move)-1];
+	$move = substr( $move, 0, strlen($move)-1 );
   }
   // remove trailing '=', if present
   if ($move{strlen($move)-1} == '=') {
-    $move = substr($move, 0, strlen($move)-1);
+	$move = substr($move, 0, strlen($move)-1);
   }
   if ( $pawn_upg == "P" || $pawn_upg == "K" )
-    return _MD_CHESS_MOVE_PAWN_MAY_BECOME; // "A pawn may only become either a knight, a bishop, a rook or a queen!"
+	return _MD_CHESS_MOVE_PAWN_MAY_BECOME; // "A pawn may only become either a knight, a bishop, a rook or a queen!"
 
   if ( $move[0]>='a' && $move[0]<='h' )
   {
-    /* pawn move. either it's 2 or for characters as 
+	/* pawn move. either it's 2 or for characters as 
      * listed above */
-    if ( strlen($move) == 4 )
-    {
-      if ( $move[1] != 'x' )
-        return _MD_CHESS_MOVE_USE_X; // "use x to indicate an attack"
-      $dest_x = $move[2];
-      $dest_y = $move[3];
-      $src_x  = $move[0];
-      if ( $player == 'w' )
-        $src_y  = $dest_y-1;
-      else
-        $src_y  = $dest_y+1;
-      $this->ac_move = sprintf( "P%s%dx%s%d%s", 
-                          $src_x,$src_y,$dest_x,$dest_y,
-                          $pawn_upg );
-      return "";
-    }
-    else
-    if (strlen($move) == 2 )
-    {
-      $fig = sprintf( "%sP", $player );
-      if ( $move[1] >= '1' && $move[1] <= '8' )
-      {
-        /* pawn move */
-        $pos = $this->boardCoordToIndex( $move );
-        if ( $pos == 64 ) return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $move); // "coordinate $move is invalid"
-        if ( $player == 'w' )
-        {
-          while( $pos >= 0 && $this->board[$pos] != $fig ) $pos -= 8;
-          if ( $pos < 0 ) $not_found = 1;
-        }
-        else
-        {
-          while( $pos <= 63 && $this->board[$pos] != $fig ) $pos += 8;
-          if ( $pos > 63 ) $not_found = 1;
-        }
-        $pos = $this->boardIndexToCoord( $pos );
-        if ( (isset($not_found) && $not_found) || $pos == "" ) {
-          return $this->move_msg(_MD_CHESS_MOVE_CANNOT_FIND_PAWN, $player, $move[0]); // "cannot find $player pawn in column $move[0]"
-        } else {
-          $this->ac_move = sprintf( "P%s-%s%s", $pos, $move, $pawn_upg );
-          return "";
-        }
-      }
-      else
-      {
-        /* notation: [a-h][a-h] for pawn attack no longer allowed 
+	if ( strlen($move) == 4 )
+	{
+	  if ( $move[1] != 'x' )
+		return _MD_CHESS_MOVE_USE_X; // "use x to indicate an attack"
+	  $dest_x = $move[2];
+	  $dest_y = $move[3];
+	  $src_x  = $move[0];
+	  if ( $player == 'w' )
+		$src_y  = $dest_y-1;
+	  else
+		$src_y  = $dest_y+1;
+	  $this->ac_move = sprintf( "P%s%dx%s%d%s", 
+						  $src_x,$src_y,$dest_x,$dest_y,
+						  $pawn_upg );
+	  return "";
+	}
+	else
+	if (strlen($move) == 2 )
+	{
+	  $fig = sprintf( "%sP", $player );
+	  if ( $move[1] >= '1' && $move[1] <= '8' )
+	  {
+		/* pawn move */
+		$pos = $this->boardCoordToIndex( $move );
+		if ( $pos == 64 ) return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $move); // "coordinate $move is invalid"
+		if ( $player == 'w' )
+		{
+		  while( $pos >= 0 && $this->board[$pos] != $fig ) $pos -= 8;
+		  if ( $pos < 0 ) $not_found = 1;
+		}
+		else
+		{
+		  while( $pos <= 63 && $this->board[$pos] != $fig ) $pos += 8;
+		  if ( $pos > 63 ) $not_found = 1;
+		}
+		$pos = $this->boardIndexToCoord( $pos );
+		if ( (isset($not_found) && $not_found) || $pos == "" ) {
+		  return $this->move_msg(_MD_CHESS_MOVE_CANNOT_FIND_PAWN, $player, $move[0]); // "cannot find $player pawn in column $move[0]"
+		} else {
+		  $this->ac_move = sprintf( "P%s-%s%s", $pos, $move, $pawn_upg );
+		  return "";
+		}
+	  }
+	  else
+	  {
+		/* notation: [a-h][a-h] for pawn attack no longer allowed 
          * except for history browser */
-        if ( $this->browsing_mode == 0 )
-            return _MD_CHESS_MOVE_USE_NOTATION; // "please use denotation [a-h]x[a-h][1-8] for pawn attacks (see help for more information)"
-        /* pawn attack must be only one pawn in column! */
-        $pawns = 0;
-        $start = $this->boardCoordToIndex( sprintf( "%s1", $move[0] ) );
-        if ( $start == 64 ) return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $move[0]); // "coordinate $move[0] is invalid"
-        for ( $i = 1; $i <= 8; $i++, $start+=8 )
-          if ( $this->board[$start] == $fig ) 
-          {
-            $pawns++;
-            $pawn_line = $i;
-          }
-        if ( $pawns == 0 )
-          return $this->move_msg(_MD_CHESS_MOVE_NO_PAWN, $move[0]); // "there is no pawn in column $move[0]"
-        else if ( $pawns > 1 )
-          return $this->move_msg(_MD_CHESS_MOVE_TWO_PAWNS, $move[0]); // "there is more than one pawn in column $move[0]"
-        else
-        {
-          if ( $player == 'w' )
-            $dest_line = $pawn_line+1;
-          else
-            $dest_line = $pawn_line-1;
-          $this->ac_move = sprintf( "P%s%dx%s%d", 
-                            $move[0],$pawn_line,$move[1],$dest_line );
-          return "";
-        }
-      }
-    }
+		if ( $this->browsing_mode == 0 )
+			return _MD_CHESS_MOVE_USE_NOTATION; // "please use denotation [a-h]x[a-h][1-8] for pawn attacks (see help for more information)"
+		/* pawn attack must be only one pawn in column! */
+		$pawns = 0;
+		$start = $this->boardCoordToIndex( sprintf( "%s1", $move[0] ) );
+		if ( $start == 64 ) return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $move[0]); // "coordinate $move[0] is invalid"
+		for ( $i = 1; $i <= 8; $i++, $start+=8 )
+		  if ( $this->board[$start] == $fig ) 
+		  {
+			$pawns++;
+			$pawn_line = $i;
+		  }
+		if ( $pawns == 0 )
+		  return $this->move_msg(_MD_CHESS_MOVE_NO_PAWN, $move[0]); // "there is no pawn in column $move[0]"
+		else if ( $pawns > 1 )
+		  return $this->move_msg(_MD_CHESS_MOVE_TWO_PAWNS, $move[0]); // "there is more than one pawn in column $move[0]"
+		else
+		{
+		  if ( $player == 'w' )
+			$dest_line = $pawn_line+1;
+		  else
+			$dest_line = $pawn_line-1;
+		  $this->ac_move = sprintf( "P%s%dx%s%d", 
+							$move[0],$pawn_line,$move[1],$dest_line );
+		  return "";
+		}
+	  }
+	}
   }
   else
   {
-    /* figure move */
-    $dest_coord = substr( $move, strlen($move)-2, 2 );
-    $action = $move[strlen($move)-3];
-    if ( $action != 'x' ) $action = '-';
-    if ( $player == 'w' ) 
-      $figures = $this->w_figures;
-    else
-      $figures = $this->b_figures;
-    $fig_count = 0;
-    foreach( $figures as $figure )
-      if ( $figure[0] == $move[0] )
-      {
-        $fig_count++;
-        if ( $fig_count == 1 )
-          $pos1 = substr( $figure, 1, 2 );
-        else
-          $pos2 = substr( $figure, 1, 2 );
-      }
-    if ( $fig_count == 0 )
-      return $this->move_msg(_MD_CHESS_MOVE_NO_FIGURE, $move[0], $this->getFullFigureName($move[0])); // sprintf("there is no figure %s = %s", $move[0], $this->getFullFigureName($move[0]))
-    else
-    if ( $fig_count == 1 )
-    {
-       $this->ac_move = sprintf( "%s%s%s%s",
-                      $move[0], $pos1, $action, $dest_coord ); 
-       return "";
-    }
-    else
-    {
-      /* two figures which may cause ambiguity */
-      $dest_pos = $this->boardCoordToIndex( $dest_coord );
-      if ( $dest_pos == 64 ) 
-        return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $dest_coord); // "coordinate $dest_coord is invalid"
-      $fig1_can_reach = $this->tileIsReachable( $move[0], 
-                            $this->boardCoordToIndex($pos1), $dest_pos );
-      $fig2_can_reach = $this->tileIsReachable( $move[0], 
-                            $this->boardCoordToIndex($pos2), $dest_pos );
-      if ( !$fig1_can_reach && !$fig2_can_reach )
-        return $this->move_msg(_MD_CHESS_MOVE_NEITHER_CAN_REACH, $move[0], $this->getFullFigureName($move[0]), $dest_coord); // sprintf("neither of the %s = %s can reach %s", $move[0], $this->getFullFigureName($move[0]), $dest_coord)
-      else
-      if ( $fig1_can_reach && $fig2_can_reach )
-      {
-        /* ambiguity - check whether a hint is given */
-        if ( ($action=='-' && strlen($move)==4) ||
-             ($action=='x' && strlen($move)==5) )
-          $hint = $move[1];
-        if ( empty($hint) )
-          return $this->move_msg(_MD_CHESS_MOVE_BOTH_CAN_REACH, $move[0], $this->getFullFigureName($move[0]), $dest_coord); // sprintf("both of the %s = %s can reach %s", $move[0], $this->getFullFigureName($move[0]), $dest_coord)
-        else
-        {
-          $move_fig1 = 0;
-          $move_fig2 = 0;
-          if ( $hint>='1' && $hint<='8' )
-          {
-            if ( $pos1[1]==$hint && $pos2[1]!=$hint )
-              $move_fig1 = 1;
-            if ( $pos2[1]==$hint && $pos1[1]!=$hint )
-              $move_fig2 = 1;
-          }
-          else
-          {
-            if ( $pos1[0]==$hint && $pos2[0]!=$hint )
-              $move_fig1 = 1;
-            if ( $pos2[0]==$hint && $pos1[0]!=$hint )
-              $move_fig2 = 1;
-          }
-          if ( !$move_fig1 && !$move_fig2 )
-            return _MD_CHESS_MOVE_AMBIGUOUS; // "ambiguity is not properly resolved"
-          if ( $move_fig1 )
-            $this->ac_move = sprintf( "%s%s%s%s",
-                          $move[0], $pos1, $action, $dest_coord );
-          else
-            $this->ac_move = sprintf( "%s%s%s%s",
-                          $move[0], $pos2, $action, $dest_coord );
-          return;
-        }
-      }
-      else
-      {
-        if ( $fig1_can_reach )
-          $this->ac_move = sprintf( "%s%s%s%s",
-                        $move[0], $pos1, $action, $dest_coord ); 
-        else
-          $this->ac_move = sprintf( "%s%s%s%s",
-                        $move[0], $pos2, $action, $dest_coord ); 
-        return "";
-      }
-    }
+	/* figure move */
+	$dest_coord = substr( $move, strlen($move)-2, 2 );
+	$action = $move[strlen($move)-3];
+	if ( $action != 'x' ) $action = '-';
+	if ( $player == 'w' ) 
+	  $figures = $this->w_figures;
+	else
+	  $figures = $this->b_figures;
+	$fig_count = 0;
+	foreach( $figures as $figure )
+	  if ( $figure[0] == $move[0] )
+	  {
+		$fig_count++;
+		if ( $fig_count == 1 )
+		  $pos1 = substr( $figure, 1, 2 );
+		else
+		  $pos2 = substr( $figure, 1, 2 );
+	  }
+	if ( $fig_count == 0 )
+	  return $this->move_msg(_MD_CHESS_MOVE_NO_FIGURE, $move[0], $this->getFullFigureName($move[0])); // sprintf("there is no figure %s = %s", $move[0], $this->getFullFigureName($move[0]))
+	else
+	if ( $fig_count == 1 )
+	{
+	   $this->ac_move = sprintf( "%s%s%s%s",
+					  $move[0], $pos1, $action, $dest_coord ); 
+	   return "";
+	}
+	else
+	{
+	  /* two figures which may cause ambiguity */
+	  $dest_pos = $this->boardCoordToIndex( $dest_coord );
+	  if ( $dest_pos == 64 ) 
+		return $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $dest_coord); // "coordinate $dest_coord is invalid"
+	  $fig1_can_reach = $this->tileIsReachable( $move[0], 
+							$this->boardCoordToIndex($pos1), $dest_pos );
+	  $fig2_can_reach = $this->tileIsReachable( $move[0], 
+							$this->boardCoordToIndex($pos2), $dest_pos );
+	  if ( !$fig1_can_reach && !$fig2_can_reach )
+		return $this->move_msg(_MD_CHESS_MOVE_NEITHER_CAN_REACH, $move[0], $this->getFullFigureName($move[0]), $dest_coord); // sprintf("neither of the %s = %s can reach %s", $move[0], $this->getFullFigureName($move[0]), $dest_coord)
+	  else
+	  if ( $fig1_can_reach && $fig2_can_reach )
+	  {
+		/* ambiguity - check whether a hint is given */
+		if ( ($action=='-' && strlen($move)==4) ||
+			 ($action=='x' && strlen($move)==5) )
+		  $hint = $move[1];
+		if ( empty($hint) )
+		  return $this->move_msg(_MD_CHESS_MOVE_BOTH_CAN_REACH, $move[0], $this->getFullFigureName($move[0]), $dest_coord); // sprintf("both of the %s = %s can reach %s", $move[0], $this->getFullFigureName($move[0]), $dest_coord)
+		else
+		{
+		  $move_fig1 = 0;
+		  $move_fig2 = 0;
+		  if ( $hint>='1' && $hint<='8' )
+		  {
+			if ( $pos1[1]==$hint && $pos2[1]!=$hint )
+			  $move_fig1 = 1;
+			if ( $pos2[1]==$hint && $pos1[1]!=$hint )
+			  $move_fig2 = 1;
+		  }
+		  else
+		  {
+			if ( $pos1[0]==$hint && $pos2[0]!=$hint )
+			  $move_fig1 = 1;
+			if ( $pos2[0]==$hint && $pos1[0]!=$hint )
+			  $move_fig2 = 1;
+		  }
+		  if ( !$move_fig1 && !$move_fig2 )
+			return _MD_CHESS_MOVE_AMBIGUOUS; // "ambiguity is not properly resolved"
+		  if ( $move_fig1 )
+			$this->ac_move = sprintf( "%s%s%s%s",
+						  $move[0], $pos1, $action, $dest_coord );
+		  else
+			$this->ac_move = sprintf( "%s%s%s%s",
+						  $move[0], $pos2, $action, $dest_coord );
+		  return;
+		}
+	  }
+	  else
+	  {
+		if ( $fig1_can_reach )
+		  $this->ac_move = sprintf( "%s%s%s%s",
+						$move[0], $pos1, $action, $dest_coord ); 
+		else
+		  $this->ac_move = sprintf( "%s%s%s%s",
+						$move[0], $pos2, $action, $dest_coord ); 
+		return "";
+	  }
+	}
   }
 
   return $error;
@@ -1111,37 +1111,37 @@ 
   /* valid pawn moves are always non-ambigious */
   if ( $move[0] == 'P' )
   {
-    /* skip P anycase. for attacks skip source digit
+	/* skip P anycase. for attacks skip source digit
        and for moves skip source pos and - */
-    if ( $move[3] == '-' )
-      $new_move = substr( $move, 4 );
-    else
-    if ( $move[3] == 'x' )
-      $new_move = sprintf("%s%s", $move[1], substr( $move, 3 ) );
+	if ( $move[3] == '-' )
+	  $new_move = substr( $move, 4 );
+	else
+	if ( $move[3] == 'x' )
+	  $new_move = sprintf("%s%s", $move[1], substr( $move, 3 ) );
   }
   else
   {
-    /* try to remove the source position and check whether it
+	/* try to remove the source position and check whether it
      * is a non-ambigious move. if it is add one of the components
      * and check again */
-    if ( $move[3] == '-' )
-      $dest = substr( $move, 4 );
-    else
-    if ( $move[3] == 'x' )
-      $dest = substr( $move, 3 );
-    $new_move = sprintf("%s%s", $move[0], $dest );
-    if ( $this->completeMove($player,$new_move) != "" )
-    {
-      /* add a component */
-      $new_move = sprintf("%s%s%s", $move[0], $move[1], $dest );
-      if ( $this->completeMove($player,$new_move) != "" )
-      {
-        /* add other component */
-        $new_move = sprintf("%s%s%s", $move[0], $move[2], $dest );
-        if ( $this->completeMove($player,$new_move) != "" )
-           $new_move = $move; /* give up */
-      }
-    }
+	if ( $move[3] == '-' )
+	  $dest = substr( $move, 4 );
+	else
+	if ( $move[3] == 'x' )
+	  $dest = substr( $move, 3 );
+	$new_move = sprintf("%s%s", $move[0], $dest );
+	if ( $this->completeMove($player,$new_move) != "" )
+	{
+	  /* add a component */
+	  $new_move = sprintf("%s%s%s", $move[0], $move[1], $dest );
+	  if ( $this->completeMove($player,$new_move) != "" )
+	  {
+		/* add other component */
+		$new_move = sprintf("%s%s%s", $move[0], $move[2], $dest );
+		if ( $this->completeMove($player,$new_move) != "" )
+		   $new_move = $move; /* give up */
+	  }
+	}
   }
   
   $this->ac_move = $old_ac_move;
@@ -1175,14 +1175,14 @@ 
   $cur_player = $this->gamestate['fen_active_color']; /* b or w */
 
   if ($cur_player != 'w' and $cur_player != 'b') {
-    return(array(false, "handleMove, internal error: player='$cur_player'"));
+	return(array(false, "handleMove, internal error: player='$cur_player'"));
   }
 
   $cur_opp = ($cur_player == 'w') ? 'b' : 'w';
 
   if ($this->gamestate['pgn_result'] != '*')
   { 
-    return(array(false, _MD_CHESS_MOVE_GAME_OVER));
+	return(array(false, _MD_CHESS_MOVE_GAME_OVER));
   }
 
 	// get castling availability flags
@@ -1327,83 +1327,83 @@ 
 
   else
   {
-    /* [PRNBQK][a-h][1-8][-:x][a-h][1-8][RNBQK] full move */
+	/* [PRNBQK][a-h][1-8][-:x][a-h][1-8][RNBQK] full move */
 
-    /* allow short move description by autocompleting to
+	/* allow short move description by autocompleting to
      * full description */
-    $ac_error = $this->completeMove( $cur_player, trim($move) );
-    if ( $ac_error != "" )
-      return(array(false, $ac_error)); // "ERROR: autocomplete: $ac_error"
-    else 
-      $move = $this->ac_move;
-    $this->last_move = str_replace( "?", "", $move );
+	$ac_error = $this->completeMove( $cur_player, trim($move) );
+	if ( $ac_error != "" )
+	  return(array(false, $ac_error)); // "ERROR: autocomplete: $ac_error"
+	else 
+	  $move = $this->ac_move;
+	$this->last_move = str_replace( "?", "", $move );
     
-    /* a final captial letter may only be N,B,R,Q for the
+	/* a final captial letter may only be N,B,R,Q for the
      * appropiate chessman */
-    $c = $move[strlen($move)-1];
-    if ( $c >= 'A' && $c <= 'Z' )
-    if ( $c != 'N' && $c != 'B' && $c != 'R' && $c != 'Q' )
-      return(array(false, _MD_CHESS_MOVE_INVALID_PIECE)); // "ERROR: only N (knight), B (bishop), R (rook) and Q (queen) are valid chessman identifiers"
+	$c = $move[strlen($move)-1];
+	if ( $c >= 'A' && $c <= 'Z' )
+	if ( $c != 'N' && $c != 'B' && $c != 'R' && $c != 'Q' )
+	  return(array(false, _MD_CHESS_MOVE_INVALID_PIECE)); // "ERROR: only N (knight), B (bishop), R (rook) and Q (queen) are valid chessman identifiers"
     
-    /* if it is a full move, try to shorten the history move */
-    if ( strlen( $history_move ) >= 6 )
-      $history_move = 
-          $this->convertFullToChessNotation($cur_player,$history_move);
-    /* DEBUG: echo "Move: $move ($history_move)<BR>"; */
+	/* if it is a full move, try to shorten the history move */
+	if ( strlen( $history_move ) >= 6 )
+	  $history_move = 
+		  $this->convertFullToChessNotation($cur_player,$history_move);
+	/* DEBUG: echo "Move: $move ($history_move)<BR>"; */
     
-    /* validate figure and position */
-    $fig_type = $move[0];
-    $fig_name = $this->getFullFigureName( $fig_type );
-    if ( $fig_name == "empty" )
-      return(array(false, $this->move_msg(_MD_CHESS_MOVE_UNKNOWN_FIGURE, $fig_type))); // "ERROR: Figure $fig_type is unknown!"
-    $fig_coord = substr($move,1,2);
-    $fig_pos = $this->boardCoordToIndex( $fig_coord );
-    if ( $fig_pos == 64 ) return(array(false, $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $fig_coord))); // "ERROR: $fig_coord is invalid!"
-    /* DEBUG  echo "fig_type: $fig_type, fig_pos: $fig_pos<BR>"; */
-    if ($this->is_empty_tile($fig_pos))
-      return(array(false, $this->move_msg(_MD_CHESS_MOVE_TILE_EMPTY, $fig_coord))); // "ERROR: Tile $fig_coord is empty."
-    if ( $this->board[$fig_pos]{0} != $cur_player )
-      return(array(false, _MD_CHESS_MOVE_NOT_YOUR_PIECE)); // "ERROR: Figure does not belong to you!"
-    if ( $this->board[$fig_pos]{1} != $fig_type )
-      return(array(false, _MD_CHESS_MOVE_NOEXIST_FIGURE)); // "ERROR: Figure does not exist!"
+	/* validate figure and position */
+	$fig_type = $move[0];
+	$fig_name = $this->getFullFigureName( $fig_type );
+	if ( $fig_name == "empty" )
+	  return(array(false, $this->move_msg(_MD_CHESS_MOVE_UNKNOWN_FIGURE, $fig_type))); // "ERROR: Figure $fig_type is unknown!"
+	$fig_coord = substr($move,1,2);
+	$fig_pos = $this->boardCoordToIndex( $fig_coord );
+	if ( $fig_pos == 64 ) return(array(false, $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $fig_coord))); // "ERROR: $fig_coord is invalid!"
+	/* DEBUG  echo "fig_type: $fig_type, fig_pos: $fig_pos<BR>"; */
+	if ($this->is_empty_tile($fig_pos))
+	  return(array(false, $this->move_msg(_MD_CHESS_MOVE_TILE_EMPTY, $fig_coord))); // "ERROR: Tile $fig_coord is empty."
+	if ( $this->board[$fig_pos]{0} != $cur_player )
+	  return(array(false, _MD_CHESS_MOVE_NOT_YOUR_PIECE)); // "ERROR: Figure does not belong to you!"
+	if ( $this->board[$fig_pos]{1} != $fig_type )
+	  return(array(false, _MD_CHESS_MOVE_NOEXIST_FIGURE)); // "ERROR: Figure does not exist!"
     
-    /* get target index */
-    $dest_coord = substr($move,4,2);
-    $dest_pos = $this->boardCoordToIndex( $dest_coord );
-    if ( $dest_pos == 64 )
-      return(array(false, $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $dest_coord))); // "ERROR: $dest_coord is invalid!"
-    if ( $dest_pos == $fig_pos )
-      return(array(false, _MD_CHESS_MOVE_START_END_SAME));
-    /* DEBUG  echo "dest_pos: $dest_pos<BR>"; */
-
-    /* get action */
-    $action = $move[3];
-    if ( $move[3] == "-" ) 
-      $action = 'M'; /* move */
-    else if ( $move[3] == 'x' )
-      $action = 'A'; /* attack */
-    else
-      return(array(false, $this->move_msg(_MD_CHESS_MOVE_UNKNOWN_ACTION, $action))); // "ERROR: $action is unknown! Please use \"-\" for a move and \"x\" for an attack."
-
-    /* if attack an enemy unit must be present on tile
+	/* get target index */
+	$dest_coord = substr($move,4,2);
+	$dest_pos = $this->boardCoordToIndex( $dest_coord );
+	if ( $dest_pos == 64 )
+	  return(array(false, $this->move_msg(_MD_CHESS_MOVE_COORD_INVALID, $dest_coord))); // "ERROR: $dest_coord is invalid!"
+	if ( $dest_pos == $fig_pos )
+	  return(array(false, _MD_CHESS_MOVE_START_END_SAME));
+	/* DEBUG  echo "dest_pos: $dest_pos<BR>"; */
+
+	/* get action */
+	$action = $move[3];
+	if ( $move[3] == "-" ) 
+	  $action = 'M'; /* move */
+	else if ( $move[3] == 'x' )
+	  $action = 'A'; /* attack */
+	else
+	  return(array(false, $this->move_msg(_MD_CHESS_MOVE_UNKNOWN_ACTION, $action))); // "ERROR: $action is unknown! Please use \"-\" for a move and \"x\" for an attack."
+
+	/* if attack an enemy unit must be present on tile
      * and if move then tile must be empty. in both cases
      * the king must not be checked after moving. */
      
-    /* check whether the move is along a valid path and
+	/* check whether the move is along a valid path and
      * whether all tiles in between are empty thus the path
      * is not blocked. the final destination tile is not 
      * checked here. */
-    if ( $fig_type != 'P' )
-    {
-        if ( !$this->tileIsReachable( $fig_type, $fig_pos, $dest_pos ) )
-          return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of moving range for $fig_name at $fig_coord!"
-    }
-    else {
-      if ( $action == 'M' && !$this->checkPawnMove( $fig_pos, $dest_pos ) )
-          return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of moving range for $fig_name at $fig_coord!"
-      if ( $action == 'A' && !$this->checkPawnAttack( $fig_pos, $dest_pos ) )
-          return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of attacking range for $fig_name at $fig_coord!"
-    }
+	if ( $fig_type != 'P' )
+	{
+		if ( !$this->tileIsReachable( $fig_type, $fig_pos, $dest_pos ) )
+		  return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of moving range for $fig_name at $fig_coord!"
+	}
+	else {
+	  if ( $action == 'M' && !$this->checkPawnMove( $fig_pos, $dest_pos ) )
+		  return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of moving range for $fig_name at $fig_coord!"
+	  if ( $action == 'A' && !$this->checkPawnAttack( $fig_pos, $dest_pos ) )
+		  return(array(false, $this->move_msg(_MD_CHESS_MOVE_OUT_OF_RANGE, $dest_coord, $fig_name, $fig_coord))); // "ERROR: Tile $dest_coord is out of attacking range for $fig_name at $fig_coord!"
+	}
      
 	$en_passant_capture_performed = 0; // 1 if en passant captured occurred, else 0
 	/* check action */
@@ -1427,43 +1427,43 @@ 
 		return(array(false, $this->move_msg(_MD_CHESS_MOVE_ATTACK_SELF, $dest_coord))); // "ERROR: You cannot attack own unit at $dest_coord."
 	}
 
-    /* backup affected tiles */
-    $old_fig_tile = $this->board[$fig_pos];
-    $old_dest_tile = $this->board[$dest_pos];
-
-    /* perform move */
-    $this->clear_tile($fig_pos);
-    if (!$this->is_empty_tile($dest_pos))
-      $this->piece_captured = sprintf("%s%s",$this->board[$dest_pos],$dest_pos);
-    $this->board[$dest_pos] = "$cur_player$fig_type";
-    if ( $en_passant_capture_performed ) {
-      /* kill pawn */
-      if ( $cur_player == 'w' ) 
-      {
-        $this->clear_tile($dest_pos - 8);
-        $this->piece_captured = sprintf("bP%s",$dest_pos-8);
-      }
-      else
-      {
-        $this->clear_tile($dest_pos + 8);
-        $this->piece_captured = sprintf("wP%s",$dest_pos+8);
-      }
-    }
-
-    /* check check :) */
-    if ( $this->kingIsUnderAttack( $cur_player, $cur_opp ) )
-    {
-      $this->board[$fig_pos] = $old_fig_tile;
-      $this->board[$dest_pos] = $old_dest_tile;
-      if ( $en_passant_capture_performed ) {
-       // restore pawn that was captured above, since that move is invalid
-        if ( $cur_player == 'w' ) 
-          $this->board[$dest_pos-8] = "bP";
-        else
-          $this->board[$dest_pos+8] = "wP";
-      }
-      return(array(false, _MD_CHESS_MOVE_IN_CHECK)); // "ERROR: Move is invalid because king would be under attack then."
-    }
+	/* backup affected tiles */
+	$old_fig_tile = $this->board[$fig_pos];
+	$old_dest_tile = $this->board[$dest_pos];
+
+	/* perform move */
+	$this->clear_tile($fig_pos);
+	if (!$this->is_empty_tile($dest_pos))
+	  $this->piece_captured = sprintf("%s%s",$this->board[$dest_pos],$dest_pos);
+	$this->board[$dest_pos] = "$cur_player$fig_type";
+	if ( $en_passant_capture_performed ) {
+	  /* kill pawn */
+	  if ( $cur_player == 'w' ) 
+	  {
+		$this->clear_tile($dest_pos - 8);
+		$this->piece_captured = sprintf("bP%s",$dest_pos-8);
+	  }
+	  else
+	  {
+		$this->clear_tile($dest_pos + 8);
+		$this->piece_captured = sprintf("wP%s",$dest_pos+8);
+	  }
+	}
+
+	/* check check :) */
+	if ( $this->kingIsUnderAttack( $cur_player, $cur_opp ) )
+	{
+	  $this->board[$fig_pos] = $old_fig_tile;
+	  $this->board[$dest_pos] = $old_dest_tile;
+	  if ( $en_passant_capture_performed ) {
+	   // restore pawn that was captured above, since that move is invalid
+		if ( $cur_player == 'w' ) 
+		  $this->board[$dest_pos-8] = "bP";
+		else
+		  $this->board[$dest_pos+8] = "wP";
+	  }
+	  return(array(false, _MD_CHESS_MOVE_IN_CHECK)); // "ERROR: Move is invalid because king would be under attack then."
+	}
 
 	// check whether this forbids any castling
 	if ($fig_type == 'K') {
@@ -1501,29 +1501,29 @@ 
 		$this->gamestate['fen_en_passant_target_square'] = '-';
 	}
 
-    if ($action == 'M' )
-      $result = $this->move_msg(_MD_CHESS_MOVE_MOVED, $fig_name, $fig_coord, $dest_coord);
-    else
-      $result = $this->move_msg(_MD_CHESS_MOVE_CAPTURED, $fig_name, $dest_coord, $fig_coord);
+	if ($action == 'M' )
+	  $result = $this->move_msg(_MD_CHESS_MOVE_MOVED, $fig_name, $fig_coord, $dest_coord);
+	else
+	  $result = $this->move_msg(_MD_CHESS_MOVE_CAPTURED, $fig_name, $dest_coord, $fig_coord);
     
-    /* if pawn reached last line convert into a queen */
-    if ( $fig_type == 'P' )
-    {
-      if ( ($cur_player=='w' && $dest_pos>= 56) || 
-           ($cur_player=='b' && $dest_pos<= 7 ) )
-      {
-        $pawn_upg = $move[strlen($move)-1];
-        if ( $pawn_upg == '?' ) 
-        {
-          $pawn_upg = 'Q';
-          $history_move = sprintf( "%sQ", $history_move );
-        }
-        $this->board[$dest_pos] = "$cur_player$pawn_upg";
-        $result .= ' ... ' . $this->move_msg(_MD_CHESS_MOVE_PROMOTED, $this->getFullFigureName($pawn_upg));
-      }
-    }
+	/* if pawn reached last line convert into a queen */
+	if ( $fig_type == 'P' )
+	{
+	  if ( ($cur_player=='w' && $dest_pos>= 56) || 
+		   ($cur_player=='b' && $dest_pos<= 7 ) )
+	  {
+		$pawn_upg = $move[strlen($move)-1];
+		if ( $pawn_upg == '?' ) 
+		{
+		  $pawn_upg = 'Q';
+		  $history_move = sprintf( "%sQ", $history_move );
+		}
+		$this->board[$dest_pos] = "$cur_player$pawn_upg";
+		$result .= ' ... ' . $this->move_msg(_MD_CHESS_MOVE_PROMOTED, $this->getFullFigureName($pawn_upg));
+	  }
+	}
   
-    $move_handled = 1;
+	$move_handled = 1;
   }
   
   /* if a legal move was performed test whether you
@@ -1752,19 +1752,19 @@ 
   //echo $coord," --> ";
   switch ( $coord[0] ) 
   {
-    case 'a': $x = 0; break;
-    case 'b': $x = 1; break;
-    case 'c': $x = 2; break;
-    case 'd': $x = 3; break;
-    case 'e': $x = 4; break;
-    case 'f': $x = 5; break;
-    case 'g': $x = 6; break;
-    case 'h': $x = 7; break;
-    default: return 64; /* erronous coord */
+	case 'a': $x = 0; break;
+	case 'b': $x = 1; break;
+	case 'c': $x = 2; break;
+	case 'd': $x = 3; break;
+	case 'e': $x = 4; break;
+	case 'f': $x = 5; break;
+	case 'g': $x = 6; break;
+	case 'h': $x = 7; break;
+	default: return 64; /* erronous coord */
   }
   $y = $coord[1]-1; 
   if ( $y < 0 || $y > 7 )
-    return 64; /* erronous coord */
+	return 64; /* erronous coord */
   $index = $y * 8 + $x;
   //echo "$index | ";
   return $index;
@@ -1782,7 +1782,7 @@ 
 {
   //echo $index," --> ";
   if ( $index < 0 || $index > 63 )
-    return "";
+	return "";
   $y = floor($index/8)+1;
   $x = chr( ($index%8)+97 );
   $coord = "$x$y";