src/hlvariant/sho-shogi/legalitycheck.h

   1 /*
   2   Copyright (c) 2007 Paolo Capriotti <p.capriotti@sns.it>
   3             (c) 2007 Maurizio Monge <maurizio.monge@kdemail.net>
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9 */
  10
  11 #ifndef HLVARIANT__SHOSHOGI__LEGALITYCHECK_H
  12 #define HLVARIANT__SHOSHOGI__LEGALITYCHECK_H
  13
  14 #include "interactiontype.h"
  15 #include "../shogi/legalitycheck.h"
  16
  17 namespace HLVariant {
  18 namespace ShoShogi {
  19
  20 template <typename _GameState>
  21 class LegalityCheck: public Shogi::LegalityCheck<_GameState> {
  22   typedef Shogi::LegalityCheck<_GameState> Base;
  23 public:
  24   typedef _GameState GameState;
  25   typedef typename GameState::Board Board;
  26   typedef typename Board::Piece Piece;
  27   typedef typename GameState::Move Move;
  28
  29   LegalityCheck(const GameState& state);
  30   bool legal(Move& move) const;
  31   virtual InteractionType droppable(const TurnTest&, int index) const;
  32 };
  33
  34 // IMPLEMENTATION
  35
  36 template <typename GameState>
  37 LegalityCheck<GameState>::LegalityCheck(const GameState& state)
  38 : Base(state) { }
  39
  40 template <typename GameState>
  41 InteractionType LegalityCheck<GameState>::droppable(const TurnTest&, int) const {
  42   return NoAction;
  43 }
  44
  45 template <typename GameState>
  46 bool LegalityCheck<GameState>::legal(Move& move) const {
  47   if (!pseudolegal(move))
  48     return false;
  49
  50   GameState tmp(Base::m_state);
  51   tmp.move(move);
  52
  53   // find king and prince positions
  54   Point king_pos = tmp.board().find(Piece(Base::m_state.turn(), Piece::KING));
  55   Point prince_pos = tmp.board().find(Piece(Base::m_state.turn(), Piece::DRUNKEN_ELEPHANT, true));
  56
  57   // check if the king and prince can be captured
  58   if ((canBeCaptured(tmp, king_pos) && canBeCaptured(tmp, prince_pos)) ||
  59       (canBeCaptured(tmp, king_pos) && !prince_pos.valid()) ||
  60       (canBeCaptured(tmp, prince_pos) && !king_pos.valid()) ||
  61       (!prince_pos.valid() && !king_pos.valid()))
  62     return false;
  63
  64   return true;
  65 }
  66
  67 } // namespace ShoShogi
  68 } // namespace HLVariant
  69
  70 #endif // HLVARIANT__SHOSHOGI__LEGALITYCHECK_H