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| author | eug-vs <eugene@eug-vs.xyz> | 2023-02-01 14:23:59 +0300 |
|---|---|---|
| committer | eug-vs <eugene@eug-vs.xyz> | 2023-02-01 14:48:40 +0300 |
| commit | 46abb37e60667445d10791553bdb307d52661180 (patch) | |
| tree | a042ac6d97dfcd4282c9726a4a3539f9b82cac73 /src/board/mod.rs | |
| parent | 7a8845f9d089d9b5b70c5842d1d77e157374ac75 (diff) | |
| download | chessnost-46abb37e60667445d10791553bdb307d52661180.tar.gz | |
fix: do not overcount EP square in move generation
Diffstat (limited to 'src/board/mod.rs')
| -rw-r--r-- | src/board/mod.rs | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/src/board/mod.rs b/src/board/mod.rs index fd0ff25..3f37d62 100644 --- a/src/board/mod.rs +++ b/src/board/mod.rs @@ -269,7 +269,14 @@ impl Board { PieceType::Pawn => { for source in serialize_bitboard(*piece) { let ep_bitboard = match self.ep_target { - Some(square) => square.to_bitboard(), + Some(square) => { + let rank = square.rank(); + if (rank == 2 && color == Color::Black) || (rank == 5 && color == Color::White) { + square.to_bitboard() + } else { + 0 + } + } None => 0, }; for target in serialize_bitboard(self.attacks.pawn[color as usize][source as usize] & capture_targets) { @@ -431,6 +438,7 @@ impl Board { } /// Count pseudo-legal moves without actually generating them + /// Also exclude all moves that put a piece under attack of a pawn - so called safe mobility pub fn mobility(&self, color: Color) -> f32 { let mut mobility = 0.; let opponent_occupancy = self.color_occupancy(color.flip()); @@ -453,7 +461,14 @@ impl Board { PieceType::Pawn => { for source in serialize_bitboard(*piece) { let ep_bitboard = match self.ep_target { - Some(square) => square.to_bitboard(), + Some(square) => { + let rank = square.rank(); + if (rank == 2 && color == Color::Black) || (rank == 5 && color == Color::White) { + square.to_bitboard() + } else { + 0 + } + } None => 0, }; mobility += pop_count(self.attacks.pawn[color as usize][source as usize] & (opponent_occupancy | ep_bitboard)) as f32; |