// Royals

def +k not sub EMPEROR #1 and <= distance #0 #1 24;
def +K not sub EMPEROR #1 and <= distance #0 #1 24;

def +kX spaces and #0;
def +KX spaces and #0;

// Subroutines

set broyals cp k +de +cp +k;
set wroyals CP K +DE +CP +K;

sub EMPEROR to; // Emperor
  if match moved (intersection nolower #wpieces):
    if match old #broyals:
      if sub checked #to;
        return true;
      else:
        return false;
      endif;
    else:
      return false;
    endif;
  else:
    if match old #wroyals:
      if sub checked #to;
        return true;
      else:
        return false;
      endif;
    else:
      return false;
    endif;
  endif;
endsub;

// This subroutine checks whether a King is in check.

sub checked king:
  my from piece;
  if match cond empty #king moved space #king (intersection nolower #wpieces):
    def enemies intersection noupper #bpieces;
  else:
    def enemies intersection nolower #wpieces;
  endif;
  for (from piece) fn enemies:
    if fn #piece #from #king:
      return #from;
    endif;
  next;
  return false;
endsub;

// Stalemated Subroutine

sub stalemated kingpos:
  store;
  local from piece to;

  if isupper #kingpos:
    def friends intersection nolower #wpieces;
    def friend match #0 #wpieces;
  else:
    def friends intersection noupper #bpieces;
    def friend match #0 #bpieces;
  endif;

  set firstpart true;
  store;
  
 // Can any piece legally move?
  for (from piece) fn friends:
    for to fn join #piece X #from:
      if fn #piece #from #to and not fn friend space #to and onboard #to:
        move #from #to;
            setlegal #from #to;
      endif;
      restore;
    next;
  next;

  // All done. Set $legalmoves and return;
  return cond count system legalmoves false true;
endsub;