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Add 'Color::slide_board_with_blockers'

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This commit is contained in:
Bruno BELANYI 2022-07-20 18:48:22 +02:00
parent b3222276ab
commit 500e6fd22f
1 changed files with 41 additions and 1 deletions
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42
src/board/direction.rs
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@ -121,7 +121,19 @@ impl Direction {
/// It does not make sense to use this method with knight-only directions, and it will panic in
/// debug-mode if it happens.
#[inline(always)]
pub fn slide_board(self, mut board: Bitboard) -> Bitboard {
pub fn slide_board(self, board: Bitboard) -> Bitboard {
self.slide_board_with_blockers(board, Bitboard::EMPTY)
}
/// Slide a board along the given [Direction], i.e: return all successive applications of
/// [Direction::move_board] until no new squares can be reached.
/// Take into account the `blockers` [Bitboard]: a combination of all pieces on the board which
/// cannot be slided over. The slide is over once a square that is part of `blockers` is
/// reached.
/// It does not make sense to use this method with knight-only directions, and it will panic in
/// debug-mode if it happens.
#[inline(always)]
pub fn slide_board_with_blockers(self, mut board: Bitboard, blockers: Bitboard) -> Bitboard {
debug_assert!(!Self::KNIGHT_DIRECTIONS.contains(&self));
let mut res = Default::default();
@ -129,6 +141,9 @@ impl Direction {
while !board.is_empty() {
board = self.move_board(board);
res = res | board;
if !(board & blockers).is_empty() {
break;
}
}
res
@ -655,4 +670,29 @@ mod test {
Bitboard::DIAGONAL - Square::A1
);
}
#[test]
fn blocked_slides() {
assert_eq!(
Direction::North
.slide_board_with_blockers(Square::A1.into_bitboard(), Square::A2.into_bitboard()),
Square::A2.into_bitboard()
);
assert_eq!(
Direction::North
.slide_board_with_blockers(Square::A1.into_bitboard(), Square::A3.into_bitboard()),
Square::A2 | Square::A3
);
assert_eq!(
Direction::North
.slide_board_with_blockers(Square::A1.into_bitboard(), Square::A4.into_bitboard()),
Square::A2 | Square::A3 | Square::A4
);
// Ensure that the starting square being in `blockers` is not an issue
assert_eq!(
Direction::North
.slide_board_with_blockers(Square::A1.into_bitboard(), Square::A1.into_bitboard()),
File::A.into_bitboard() - Square::A1
);
}
}