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Fix asymmetric evaluation terms on non-8x8 boards #19

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Fix asymmetric evaluation terms on non-8x8 boards #19

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27 changes: 18 additions & 9 deletions src/evaluate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -445,8 +445,11 @@ namespace {

constexpr Color Them = ~Us;
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
const Rank maxRank = pos.max_rank();
Bitboard outpostRanks = Bitboard(0);
for (int r = int(RANK_4); r <= int(RANK_6) && r <= int(maxRank); ++r)
outpostRanks |= rank_bb(relative_rank(Us, Rank(r), maxRank));
outpostRanks &= pos.board_bb();
Bitboard b1 = pos.pieces(Us, Pt);
Bitboard b, bb;
Score score = SCORE_ZERO;
Expand Down Expand Up @@ -526,7 +529,7 @@ namespace {
{
// Bonus if the piece is on an outpost square or can reach one
// Bonus for knights (UncontestedOutpost) if few relevant targets
bb = OutpostRanks & (attackedBy[Us][PAWN] | shift<Down>(pos.pieces(PAWN)))
bb = outpostRanks & (attackedBy[Us][PAWN] | shift<Down>(pos.pieces(PAWN)))
& ~pe->pawn_attacks_span(Them);
Bitboard targets = pos.pieces(Them) & ~pos.pieces(PAWN);

Expand Down Expand Up @@ -841,7 +844,10 @@ namespace {

constexpr Color Them = ~Us;
constexpr Direction Up = pawn_push(Us);
constexpr Bitboard TRank3BB = (Us == WHITE ? Rank3BB : Rank6BB);
const Rank maxRank = pos.max_rank();
Bitboard thirdRank = Bitboard(0);
if (int(maxRank) >= int(RANK_3))
thirdRank = rank_bb(relative_rank(Us, RANK_3, maxRank)) & pos.board_bb();

Bitboard b, weak, defended, nonPawnEnemies, stronglyProtected, safe;
Score score = SCORE_ZERO;
Expand Down Expand Up @@ -951,7 +957,7 @@ namespace {

// Find squares where our pawns can push on the next move
b = shift<Up>(pos.pieces(Us, PAWN)) & ~pos.pieces();
b |= shift<Up>(b & TRank3BB) & ~pos.pieces();
b |= shift<Up>(b & thirdRank) & ~pos.pieces();

// Keep only the squares which are relatively safe
b &= ~attackedBy[Them][PAWN] & safe;
Expand Down Expand Up @@ -1140,12 +1146,15 @@ namespace {

constexpr Color Them = ~Us;
constexpr Direction Down = -pawn_push(Us);
constexpr Bitboard SpaceMask =
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);
const Rank maxRank = pos.max_rank();
Bitboard spaceMask = CenterFiles & pos.board_bb();
Bitboard rankMask = Bitboard(0);
for (int r = int(RANK_2); r <= int(RANK_4) && r <= int(maxRank); ++r)
rankMask |= rank_bb(relative_rank(Us, Rank(r), maxRank));
spaceMask &= rankMask;

// Find the available squares for our pieces inside the area defined by SpaceMask
Bitboard safe = SpaceMask
Bitboard safe = spaceMask
& ~pos.pieces(Us, PAWN)
& ~attackedBy[Them][PAWN];

Expand Down
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