RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-25 18:17:44 +00:00
Code Issues Activity Actions

Chess: Add new ways to draw.

Browse source 
new ways:
Insufficent material
Threefold/Fivefold repitition
50 move/75 move rule
This commit is contained in:
Peter Elliott 2020-08-12 14:41:35 -06:00 • committed by Andreas Kling
parent 9a817270e8
commit d90f8abe9d
3 changed files with 154 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

91
Games/Chess/Chess.cpp
View file

@ -305,9 +305,17 @@ bool Chess::apply_move(const Move& move, Colour colour)
bool Chess::apply_illegal_move(const Move& move, Colour colour)
{
Chess clone = *this;
clone.m_previous_states = {};
auto state_count = 0;
if (m_previous_states.contains(clone))
state_count = m_previous_states.get(clone).value();
m_previous_states.set(clone, state_count + 1);
m_turn = opposing_colour(colour);
m_last_move = move;
m_moves_since_capture++;
if (move.from == Square("a1") || move.to == Square("a1") || move.from == Square("e1"))
m_white_can_castle_queenside = false;
@ -362,8 +370,12 @@ bool Chess::apply_illegal_move(const Move& move, Colour colour)
} else {
set_piece({ move.to.rank + 1, move.to.file }, EmptyPiece);
}
m_moves_since_capture = 0;
}
if (get_piece(move.to).colour != Colour::None)
m_moves_since_capture = 0;
set_piece(move.to, get_piece(move.from));
set_piece(move.from, EmptyPiece);
@ -372,6 +384,44 @@ bool Chess::apply_illegal_move(const Move& move, Colour colour)
Chess::Result Chess::game_result() const
{
bool sufficient_material = false;
bool no_more_pieces_allowed = false;
Optional<Square> bishop;
Square::for_each([&](Square sq) {
if (get_piece(sq).type == Type::Queen || get_piece(sq).type == Type::Rook || get_piece(sq).type == Type::Pawn) {
sufficient_material = true;
return IterationDecision::Break;
}
if (get_piece(sq).type != Type::None && get_piece(sq).type != Type::King && no_more_pieces_allowed) {
sufficient_material = true;
return IterationDecision::Break;
}
if (get_piece(sq).type == Type::Knight)
no_more_pieces_allowed = true;
if (get_piece(sq).type == Type::Bishop) {
if (bishop.has_value()) {
if (get_piece(sq).colour == get_piece(bishop.value()).colour) {
sufficient_material = true;
return IterationDecision::Break;
} else if (sq.is_light() != bishop.value().is_light()) {
sufficient_material = true;
return IterationDecision::Break;
}
no_more_pieces_allowed = true;
} else {
bishop = sq;
}
}
return IterationDecision::Continue;
});
if (!sufficient_material)
return Result::InsufficientMaterial;
bool are_legal_moves = false;
generate_moves([&](Move m) {
(void)m;
@ -379,8 +429,22 @@ Chess::Result Chess::game_result() const
return IterationDecision::Break;
});
if (are_legal_moves)
if (are_legal_moves) {
if (m_moves_since_capture >= 75 * 2)
return Result::SeventyFiveMoveRule;
if (m_moves_since_capture == 50 * 2)
return Result::FiftyMoveRule;
auto repeats = m_previous_states.get(*this);
if (repeats.has_value()) {
if (repeats.value() == 3)
return Result::ThreeFoldRepitition;
if (repeats.value() >= 5)
return Result::FiveFoldRepitition;
}
return Result::NotFinished;
}
if (in_check(turn()))
return Result::CheckMate;
@ -401,3 +465,28 @@ bool Chess::is_promotion_move(const Move& move, Colour colour) const
return false;
}
bool Chess::operator==(const Chess& other) const
{
bool equal_squares = true;
Square::for_each([&](Square sq) {
if (get_piece(sq) != other.get_piece(sq)) {
equal_squares = false;
return IterationDecision::Break;
}
return IterationDecision::Continue;
});
if (!equal_squares)
return false;
if (m_white_can_castle_queenside != other.m_white_can_castle_queenside)
return false;
if (m_white_can_castle_kingside != other.m_white_can_castle_kingside)
return false;
if (m_black_can_castle_queenside != other.m_black_can_castle_queenside)
return false;
if (m_black_can_castle_kingside != other.m_black_can_castle_kingside)
return false;
return turn() == other.turn();
}