src/hlvariant/crazyhouse/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__CRAZYHOUSE__LEGALITYCHECK_H
  12 #define HLVARIANT__CRAZYHOUSE__LEGALITYCHECK_H
  13
  14 #include "../chess/legalitycheck.h"
  15
  16 namespace HLVariant {
  17 namespace Crazyhouse {
  18
  19 template <typename _GameState>
  20 class LegalityCheck : public Chess::LegalityCheck<_GameState> {
  21 public:
  22   typedef _GameState GameState;
  23 private:
  24   typedef Chess::LegalityCheck<GameState> Base;
  25   typedef typename Base::Board Board;
  26   typedef typename Base::Move Move;
  27   typedef typename Base::Piece Piece;
  28 protected:
  29   using Base::m_state;
  30 public:
  31   LegalityCheck(const GameState& state);
  32
  33   virtual bool pseudolegal(Move& move) const;
  34   virtual typename Piece::Color mover(const Move& move) const;
  35 };
  36
  37 // IMPLEMENTATION
  38
  39 template <typename GameState>
  40 LegalityCheck<GameState>::LegalityCheck(const GameState& state)
  41 : Base(state) { }
  42
  43 template <typename GameState>
  44 bool LegalityCheck<GameState>::pseudolegal(Move& move) const {
  45   // add drop information to move, if missing
  46   if (move.drop() == Piece() &&
  47       move.pool() != Piece::INVALID_COLOR &&
  48       move.index() != -1) {
  49     move.setDrop(m_state.pools().pool(move.pool()).get(move.index()));
  50   }
  51
  52   Piece dropped = move.drop();
  53
  54   if (dropped == Piece()) {
  55     return Base::pseudolegal(move);
  56   }
  57   else {
  58     // dropping on a valid square
  59     if (!m_state.board().valid(move.to()))
  60       return false;
  61
  62     // cannot drop on occupied squares
  63     if (m_state.board().get(move.to()) != Piece())
  64       return false;
  65
  66     // cannot drop pawns in first or eighth rank
  67     if (dropped.type() == Piece::PAWN &&
  68           (move.to().y == m_state.startingRank(Piece::WHITE) ||
  69            move.to().y == m_state.promotionRank(Piece::WHITE)))
  70       return false;
  71
  72     return true;
  73   }
  74 }
  75
  76 template <typename GameState>
  77 typename LegalityCheck<GameState>::Piece::Color
  78 LegalityCheck<GameState>::mover(const Move& move) const {
  79   if (move.drop() != Piece())
  80     return move.drop().color();
  81   else
  82     return Base::mover(move);
  83 }
  84
  85 } // namespace Crazyhouse
  86 } // namespace HLVariant
  87
  88
  89 #endif // HLVARIANT__CRAZYHOUSE__LEGALITYCHECK_H