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Prefer names to numbers in storm code

Also replaces some tabs with spaces and
change StormDanger order to reflect
ShelterWeakness one.

No functional change.
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mcostalba committed Dec 21, 2014
1 parent e5c7b44 commit 296534f23489e6d95ba7ce1bb35e8a2cbf9a5a9d
Showing with 23 additions and 23 deletions.
  1. +23 −23 src/pawns.cpp
@@ -60,32 +60,31 @@ namespace {
// Unsupported pawn penalty
const Score UnsupportedPawnPenalty = S(20, 10);

// Weakness of our pawn shelter in front of the king indexed by [file pairs (a/h,b/g,c/f,d/e)][rank]
// Weakness of our pawn shelter in front of the king by [distance from edge][rank]
const Value ShelterWeakness[][RANK_NB] = {
{ V(101), V(10), V(24), V(68), V(90), V( 95), V(102) },
{ V(105), V( 1), V(30), V(76), V(95), V(100), V(105) },
{ V( 99), V( 0), V(32), V(72), V(92), V(101), V(100) },
{ V( 94), V( 1), V(31), V(68), V(89), V( 98), V(106) } };

// Danger of enemy pawns moving toward our king indexed by
// [file pairs (a/h,b/g,c/f,d/e)][no friendly pawn | pawn unblocked | pawn blocked by pawn| pawn blocked by king][rank of enemy pawn]
// Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
const Value StormDanger[][4][RANK_NB] = {
{ { V( 0), V( 61), V( 128), V(47), V(27) },
{ V(25), V( 33), V( 95), V(39), V(21) },
{ V( 0), V( 0), V( 80), V(14), V( 8) },
{ V( 0), V(-300), V(-300), V(54), V(23) } },
{ { V( 0), V( 66), V( 131), V(49), V(27) },
{ V( 0), V( 66), V( 131), V(49), V(27) },
{ V( 0), V( 62), V( 126), V(52), V(23) },
{ V( 0), V( 63), V( 128), V(52), V(26) } },
{ { V(25), V( 33), V( 95), V(39), V(21) },
{ V(24), V( 33), V( 97), V(42), V(22) },
{ V( 0), V( 0), V( 163), V(28), V(12) },
{ V( 0), V( 67), V( 128), V(46), V(24) } },
{ { V( 0), V( 62), V( 126), V(52), V(23) },
{ V(24), V( 33), V( 93), V(35), V(23) },
{ V(26), V( 27), V( 96), V(37), V(22) } },
{ { V( 0), V( 0), V( 80), V(14), V( 8) },
{ V( 0), V( 0), V( 163), V(28), V(12) },
{ V( 0), V( 0), V( 163), V(25), V(15) },
{ V( 0), V( 64), V( 130), V(50), V(29) } },
{ { V( 0), V( 63), V( 128), V(52), V(26) },
{ V(26), V( 27), V( 96), V(37), V(22) },
{ V( 0), V( 0), V( 161), V(24), V(14) },
{ V( 0), V( 63), V( 127), V(51), V(24) } } };
{ V( 0), V( 0), V( 161), V(24), V(14) } },
{ { V( 0), V(-300), V(-300), V(54), V(23) },
{ V( 0), V( 67), V( 128), V(46), V(24) },
{ V( 0), V( 64), V( 130), V(50), V(29) },
{ V( 0), V( 63), V( 127), V(51), V(24) } } };

// Max bonus for king safety. Corresponds to start position with all the pawns
// in front of the king and no enemy pawn on the horizon.
@@ -247,13 +246,15 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) {

const Color Them = (Us == WHITE ? BLACK : WHITE);

enum { NoFriendlyPawn, Unblocked, BlockedByPawn, BlockedByKing };

Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
Bitboard ourPawns = b & pos.pieces(Us);
Bitboard theirPawns = b & pos.pieces(Them);
Value safety = MaxSafetyBonus;
File kf = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));

for (File f = kf - File(1); f <= kf + File(1); ++f)
for (File f = center - File(1); f <= center + File(1); ++f)
{
b = ourPawns & file_bb(f);
Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
@@ -262,12 +263,11 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) {
Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;

safety -= ShelterWeakness[std::min(f, FILE_H - f)][rkUs]
+ StormDanger[std::min(f, FILE_H - f)]
[file_of(ksq) == f && relative_rank(Us, ksq) == rkThem - 1 ? 3 :
rkUs == RANK_1 ? 0 :
rkThem != rkUs + 1 ? 1 :
/* pawn blocked by pawn */ 2 ]
[rkThem];
+ StormDanger
[f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing :
rkUs == RANK_1 ? NoFriendlyPawn :
rkThem == rkUs + 1 ? BlockedByPawn : Unblocked]
[std::min(f, FILE_H - f)][rkThem];
}

return safety;

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