Account for captures in 'ChessBoard::{,un}do_move'

This is a silly thing to forget...
This commit is contained in:
Bruno BELANYI 2024-04-03 23:24:12 +01:00
parent 1646c055fd
commit adad4118ae

View file

@ -37,6 +37,7 @@ pub struct NonReversibleState {
castle_rights: [CastleRights; Color::NUM_VARIANTS],
en_passant: Option<Square>,
half_move_clock: u32, // Should *probably* never go higher than 100.
captured_piece: Option<Piece>,
}
impl ChessBoard {
@ -134,11 +135,13 @@ impl ChessBoard {
/// Play the given [Move], returning all non-revertible state (e.g: en-passant, etc...).
#[inline(always)]
pub fn do_move(&mut self, chess_move: Move) -> NonReversibleState {
let opponent = !self.current_player();
// Save non-revertible state
let state = NonReversibleState {
castle_rights: self.castle_rights,
en_passant: self.en_passant,
half_move_clock: self.half_move_clock,
captured_piece: chess_move.capture(),
};
// Non-revertible state modification
@ -167,6 +170,11 @@ impl ChessBoard {
_ => *castle_rights,
}
}
if let Some(piece) = chess_move.capture() {
*self.piece_occupancy_mut(piece) ^= chess_move.destination();
*self.color_occupancy_mut(opponent) ^= chess_move.destination();
self.combined_occupancy ^= chess_move.destination();
}
// Revertible state modification
self.xor(
@ -188,6 +196,11 @@ impl ChessBoard {
self.castle_rights = previous.castle_rights;
self.en_passant = previous.en_passant;
self.half_move_clock = previous.half_move_clock;
if let Some(piece) = previous.captured_piece {
*self.piece_occupancy_mut(piece) ^= chess_move.destination();
*self.color_occupancy_mut(self.current_player()) ^= chess_move.destination();
self.combined_occupancy ^= chess_move.destination();
}
// Restore revertible state
self.xor(
@ -837,4 +850,29 @@ mod test {
.unwrap()
);
}
#[test]
fn do_move_undo_capture() {
let mut position = ChessBoard::from_fen("3q3k/8/8/8/8/8/8/K2Q4 w - - 0 1").unwrap();
let expected = ChessBoard::from_fen("3Q3k/8/8/8/8/8/8/K7 b - - 0 1").unwrap();
let original = position.clone();
let capture = MoveBuilder {
piece: Piece::Queen,
start: Square::D1,
destination: Square::D8,
capture: Some(Piece::Queen),
promotion: None,
en_passant: false,
double_step: false,
castling: false,
}
.into();
let state = position.do_move(capture);
assert_eq!(position, expected);
position.undo_move(capture, state);
assert_eq!(position, original);
}
}