Square s;
File f;
Rank r;
- bool passed, isolated, doubled, chain, backward, candidate;
+ bool passed, isolated, doubled, opposed, chain, backward, candidate;
int bonus;
Score value = make_score(0, 0);
const Square* ptr = pos.piece_list_begin(Us, PAWN);
assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
// Passed, isolated or doubled pawn?
- passed = Position::pawn_is_passed(theirPawns, Us, s);
- isolated = Position::pawn_is_isolated(ourPawns, s);
- doubled = Position::pawn_is_doubled(ourPawns, Us, s);
+ passed = !(theirPawns & passed_pawn_mask(Us, s));
+ isolated = !(ourPawns & neighboring_files_bb(s));
+ doubled = ourPawns & squares_behind(Us, s);
+ opposed = theirPawns & squares_in_front_of(Us, s);
// We calculate kingside and queenside pawn storm
// scores for both colors. These are used when evaluating
Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
while (b)
{
+ // Give a bonus according to the distance of the nearest enemy pawn
Square s2 = pop_1st_bit(&b);
+ int v = StormLeverBonus[f] - 2 * square_distance(s, s2);
+
+ // If enemy pawn has no pawn beside itself is particularly vulnerable.
+ // Big bonus, especially against a weakness on the rook file
if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- {
- // The enemy pawn has no pawn beside itself, which makes it
- // particularly vulnerable. Big bonus, especially against a
- // weakness on the rook file.
- if (square_file(s2) == FILE_H)
- bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2);
- else
- bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2);
- } else
- // There is at least one enemy pawn beside the enemy pawn we look
- // at, which means that the pawn has somewhat better chances of
- // defending itself by advancing. Smaller bonus.
- bonus += StormLeverBonus[f] - 2*square_distance(s, s2);
+ v *= (square_file(s2) == FILE_H ? 4 : 2);
+
+ bonus += v;
}
}
pi->ksStormValue[Us] += bonus;
Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
while (b)
{
+ // Give a bonus according to the distance of the nearest enemy pawn
Square s2 = pop_1st_bit(&b);
+ int v = StormLeverBonus[f] - 4 * square_distance(s, s2);
+
+ // If enemy pawn has no pawn beside itself is particularly vulnerable.
+ // Big bonus, especially against a weakness on the rook file
if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
- {
- // The enemy pawn has no pawn beside itself, which makes it
- // particularly vulnerable. Big bonus, especially against a
- // weakness on the rook file.
- if (square_file(s2) == FILE_A)
- bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2);
- else
- bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2);
- } else
- // There is at least one enemy pawn beside the enemy pawn we look
- // at, which means that the pawn has somewhat better chances of
- // defending itself by advancing. Smaller bonus.
- bonus += StormLeverBonus[f] - 4*square_distance(s, s2);
+ v *= (square_file(s2) == FILE_A ? 4 : 2);
+
+ bonus += v;
}
}
pi->qsStormValue[Us] += bonus;
// Test for candidate passed pawn
candidate = !passed
- && !(theirPawns & file_bb(f))
+ && !opposed
&& ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(Us, r) | rank_bb(r)) & ourPawns)
- count_1s_max_15(neighboring_files_bb(f) & in_front_bb(Us, r) & theirPawns)
>= 0);