CHANGE: vshogi::animal_shogi::State::in_check() considers try rule

ctgk · Oct 10, 2024 · b7a11aa · b7a11aa
1 parent ac41116
commit b7a11aa
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Showing 3 changed files with 72 additions and 0 deletions.
diff --git a/cpp/include/vshogi/common/board.hpp b/cpp/include/vshogi/common/board.hpp
@@ -146,6 +146,10 @@ class Board
         update_internals_based_on_pieces();
         return sfen;
     }
+    BitBoardType get_attacks_by_nocheck(const Square& sq) const
+    {
+        return BitBoardType::get_attacks_by(m_pieces[sq], sq, get_occupied());
+    }
     Square find_attacker(
         const ColorEnum& attacker_color,
         const Square& attacked,

diff --git a/cpp/include/vshogi/variants/animal_shogi.hpp b/cpp/include/vshogi/variants/animal_shogi.hpp
@@ -372,6 +372,50 @@ inline animal_shogi::ColoredPieceEnum animal_shogi::Board::apply(
     return apply(dst, moving_piece, hash);
 }
 
+template <>
+inline void animal_shogi::State::update_checkers()
+{
+    using namespace animal_shogi;
+    std::fill_n(m_checker_locations, 2, SQ_NA);
+    uint index = 0u;
+    const auto king_sq = m_board.get_king_location(m_turn);
+    for (auto sq : m_board.get_attacks_by_nocheck(king_sq).square_iterator()) {
+        if (m_board.is_empty(sq))
+            continue;
+        if (m_board.get_attacks_by_nocheck(sq).is_one(king_sq))
+            m_checker_locations[index++] = sq;
+        if (index > 1)
+            return;
+    }
+    const auto mask_rank_2nd = (m_turn == BLACK) ? bb_rank3 : bb_rank2;
+    const auto enemy_king_sq = m_board.get_king_location(~m_turn);
+    if (mask_rank_2nd.is_one(enemy_king_sq))
+        m_checker_locations[index++] = enemy_king_sq;
+}
+
+template <>
+inline void
+animal_shogi::State::update_checkers_before_turn_update(const Square& dst)
+{
+    using namespace animal_shogi;
+    const auto enemy_king_sq = m_board.get_king_location(~m_turn);
+    uint index = 0u;
+    std::fill_n(m_checker_locations, 2, SQ_NA);
+    if (m_board.get_attacks_by_nocheck(dst).is_one(enemy_king_sq))
+        m_checker_locations[index++] = dst;
+    const auto king_sq = m_board.get_king_location(m_turn);
+    const auto mask_rank_3rd = (m_turn == BLACK) ? bb_rank3 : bb_rank2;
+    if (mask_rank_3rd.is_one(king_sq))
+        m_checker_locations[index++] = king_sq;
+}
+
+template <>
+inline void animal_shogi::State::update_checkers_before_turn_update(
+    const Square& dst, const Square&)
+{
+    return update_checkers_before_turn_update(dst);
+}
+
 template <>
 inline void
 animal_shogi::KingMoveGenerator::increment_iterator_while_square_is_attacked()

diff --git a/cpp/tests/test_vshogi/test_animal_shogi/test_state.cpp b/cpp/tests/test_vshogi/test_animal_shogi/test_state.cpp
@@ -99,4 +99,28 @@ TEST(animal_shogi_state, zobrist_hash)
     CHECK_TRUE(another != hash);
 }
 
+TEST(animal_shogi_state, in_check)
+{
+    {
+        const auto s = State("1l1/3/3/1L1 b -");
+        CHECK_FALSE(s.in_check());
+    }
+    {
+        const auto s = State("1l1/3/1c1/1L1 b -");
+        CHECK_TRUE(s.in_check());
+    }
+    {
+        const auto s = State("3/3/l2/2L b -");
+        CHECK_TRUE(s.in_check());
+    }
+    {
+        auto s = State("3/l2/3/1L1 b -");
+        CHECK_FALSE(s.in_check());
+        s.apply(Move(SQ_B3, SQ_B4));
+        CHECK_TRUE(s.in_check()); // B_LI is attacking W_LI
+        s.apply(Move(SQ_A3, SQ_A2));
+        CHECK_TRUE(s.in_check()); // W_LI reached the second furthest rank
+    }
+}
+
 } // namespace test_vshogi::test_animal_shogi