diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/board.rs | 50 |
1 files changed, 44 insertions, 6 deletions
diff --git a/src/board.rs b/src/board.rs index 1c06c9b..4a4e2f4 100644 --- a/src/board.rs +++ b/src/board.rs @@ -1,5 +1,10 @@ use crate::{bitboard::{Bitboard, serialize_bitboard, bitscan}, moves::{Move, MoveKind}, attacks::Attacks, square::Square}; +pub enum CastlingSide { + King, + Queen, +} + #[derive(Debug, Clone, PartialEq, Eq)] pub struct Board { pub pieces: [Bitboard; 12], @@ -10,6 +15,12 @@ pub struct Board { /// En passsant target square pub ep_target: Option<Square>, + /// Castling rights indexed by Color and CastlingSide + /// ``` + /// let can_castle = castling_rights[Color::White as usize][CastlingSide::Queen as usize]; + /// ``` + pub castling_rights: [[bool; 2]; 2], + attacks: Attacks, } @@ -91,6 +102,7 @@ impl Board { occupancy: 0, ply: 0, attacks: Attacks::new(), + castling_rights: [[true; 2]; 2], // TODO: actualy parse from FEN ep_target: None, }; board.update_occupancy(); @@ -223,7 +235,7 @@ impl Board { let all_empty = castle_line.iter().all(|square| empty & square.to_bitboard() > 0); let any_checks = castle_line.iter().any(|square| self.is_square_attacked(*square, color.flip())); - if all_empty && !any_checks { + if all_empty && !any_checks && self.castling_rights[color as usize][CastlingSide::Queen as usize] { moves.push(Move { source: king_home_position, target: king_home_position.west_one().west_one(), @@ -240,7 +252,7 @@ impl Board { let all_empty = castle_line.iter().all(|square| empty & square.to_bitboard() > 0); let any_checks = castle_line.iter().any(|square| self.is_square_attacked(*square, color.flip())); - if all_empty && !any_checks { + if all_empty && !any_checks && self.castling_rights[color as usize][CastlingSide::King as usize] { moves.push(Move { source: king_home_position, target: king_home_position.east_one().east_one(), @@ -339,7 +351,7 @@ impl Board { } // Move a piece from source square to target - match self.pieces + let source_piece = match self.pieces .iter() .enumerate() .find(|(piece_type, bitboard)| *bitboard & mov.source.to_bitboard() > 0) @@ -350,6 +362,7 @@ impl Board { self.pieces[source_piece] |= move_target_bb; self.occupancy |= move_target_bb; + PieceType::from(source_piece) }, None => panic!("Move is malformed: source piece not found"), }; @@ -390,13 +403,29 @@ impl Board { } } else { None }; + // Withdraw castling rights when moving rooks or king + match source_piece { + PieceType::King => { + self.castling_rights[Color::from_piece(source_piece) as usize][CastlingSide::King as usize] = false; + self.castling_rights[Color::from_piece(source_piece) as usize][CastlingSide::Queen as usize] = false; + }, + PieceType::Rook => { + match mov.source.file() { + 0 => self.castling_rights[Color::from_piece(source_piece) as usize][CastlingSide::Queen as usize] = false, + 7 => self.castling_rights[Color::from_piece(source_piece) as usize][CastlingSide::King as usize] = false, + _ => {}, + } + }, + _ => {}, + } + self.ply += 1; captured_piece } /// Completely reverse make_move as if it never happened - pub fn unmake_move(&mut self, mov: Move, captured_piece: Option<PieceType>, previous_ep_target: Option<Square>) { + pub fn unmake_move(&mut self, mov: Move, captured_piece: Option<PieceType>, previous_ep_target: Option<Square>, previous_castling_rights: [[bool; 2]; 2]) { let move_source_bb = mov.source.to_bitboard(); let move_target_bb = mov.target.to_bitboard(); @@ -463,6 +492,7 @@ impl Board { self.ep_target = previous_ep_target; + self.castling_rights = previous_castling_rights; self.ply -= 1; } @@ -487,6 +517,7 @@ impl Board { for mov in moves { let ep_target_before = self.ep_target.clone(); + let castling_rights_before = self.castling_rights.clone(); let captured_piece = self.make_move(mov); // King can not be in check after our own move if !self.is_king_in_check(color) { @@ -521,7 +552,7 @@ impl Board { en_passants += children_ep; } - self.unmake_move(mov, captured_piece, ep_target_before); + self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before); } if print { @@ -592,6 +623,13 @@ impl Color { Self::Black => Self::White, } } + pub fn from_piece(piece: PieceType) -> Self { + if (piece as u8) < 6 { + Self::White + } else { + Self::Black + } + } } #[cfg(test)] @@ -701,7 +739,7 @@ mod tests { let captured_piece = board.make_move(mov); board.print(); - board.unmake_move(mov, captured_piece, None); + board.unmake_move(mov, captured_piece, None, board.castling_rights); board.print(); assert_eq!(board, initial_board, "Board state after unmake_move should be the same as before make_move"); |