Files
Knightly/engine/src/bitboard/board.rs
2025-11-15 10:11:34 +01:00

110 lines
3.1 KiB
Rust

pub struct Board {
bitboards: [u64; 12], // 0-5 -> white pieces (P, N, B, R, Q, K), 6-11 -> black pieces (p, n, b, r, q, k)
piece_board: [u8; 64], // same as board indexes, 12 -> empty square
occupancy: [u64; 3], // 0 -> white, 1 -> black, 2 -> combined
castling_rights: u8, // 0b0000_KQkq
pinned_squares: [u8; 64], // 0 -> E-W, 1 -> NE-SW, 2 -> N-S, 3 -> SE-NW, 4 -> no pin
pin_mask: u64, // 1 -> pin, 0 -> no pin
en_passant_square: u64, // 1 -> ep square, 0 -> no ep square
side_to_move: u8 // 0 -> white to play, 1 -> black to play
}
impl Board {
pub fn new_clear() -> Self {
let mut bit_board: Self = Self {
bitboards: [0x0000_0000_0000_0000; 12],
piece_board: [12; 64],
occupancy: [0x0000_0000_0000_0000; 3],
castling_rights: 0b0000_0000,
pinned_squares: [4; 64],
pin_mask: 0u64,
en_passant_square: 0x0000_0000_0000_0000,
side_to_move: 0
};
return bit_board;
}
pub fn new() -> Self {
let mut bit_board: Board = Self {
bitboards: [0x0000_0000_0000_FF00,
0x0000_0000_0000_0042,
0x0000_0000_0000_0024,
0x0000_0000_0000_0081,
0x0000_0000_0000_0008,
0x0000_0000_0000_0010,
0x00FF_0000_0000_0000,
0x4200_0000_0000_0000,
0x2400_0000_0000_0000,
0x8100_0000_0000_0000,
0x0800_0000_0000_0000,
0x1000_0000_0000_0000],
piece_board: [12; 64],
occupancy: [0; 3],
castling_rights: 0b0000_1111,
pinned_squares: [4; 64],
pin_mask: 0u64,
en_passant_square: 0x0000_0000_0000_0000,
side_to_move: 0
};
bit_board.calc_occupancy();
bit_board.calc_piece_board();
return bit_board;
}
#[inline(always)]
pub fn bitboards(&self, index: usize) -> u64 {
return self.bitboards[index];
}
#[inline(always)]
pub fn piece_board(&self, sq: u8) -> u8 {
return self.piece_board[sq as usize];
}
#[inline(always)]
pub fn occupancy(&self, side: usize) -> u64 {
return self.occupancy[side];
}
#[inline(always)]
pub fn castling_rights(&self) -> u8 {
return self.castling_rights;
}
#[inline(always)]
pub fn pinned_squares(&self, sq: usize) -> u8 {
return self.pinned_squares[sq];
}
#[inline(always)]
pub fn pin_mask(&self) -> u64 {
return self.pin_mask;
}
#[inline(always)]
pub fn en_passant_square(&self) -> u64 {
return self.en_passant_square;
}
#[inline(always)]
pub fn side_to_move(&self) -> u8 {
return self.side_to_move;
}
fn calc_occupancy(&mut self) {
self.occupancy = [0u64; 3];
for b in 0..6 {
self.occupancy[0] |= self.bitboards[b];
}
for b in 6..12 {
self.occupancy[1] |= self.bitboards[b];
}
self.occupancy[2] = self.occupancy[0] | self.occupancy[1];
}
fn calc_piece_board(&mut self) {
for sq in 0..64 {
for b in 0..12 {
if (self.bitboards[b as usize] & 1 << sq) != 0 {
self.piece_board[sq] = b;
}
}
}
}
}