/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Bitboard pinnedPieces[COLOR_NB];
};
- // Evaluation grain size, must be a power of 2
- const int GrainSize = 4;
-
// Evaluation weights, initialized from UCI options
enum { Mobility, PawnStructure, PassedPawns, Space, KingDangerUs, KingDangerThem };
Score Weights[6];
// If we don't already have an unusual scale factor, check for opposite
// colored bishop endgames, and use a lower scale for those.
- if ( ei.mi->game_phase() < PHASE_MIDGAME
- && pos.opposite_bishops()
- && sf == SCALE_FACTOR_NORMAL)
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
+ && pos.opposite_bishops()
+ && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
{
// Ignoring any pawns, do both sides only have a single bishop and no
// other pieces?
else
// Endgame with opposite-colored bishops, but also other pieces. Still
// a bit drawish, but not as drawish as with only the two bishops.
- sf = ScaleFactor(50);
+ sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
}
Value v = interpolate(score, ei.mi->game_phase(), sf);
assert(ph >= PHASE_ENDGAME && ph <= PHASE_MIDGAME);
int e = (eg_value(v) * int(sf)) / SCALE_FACTOR_NORMAL;
- int r = (mg_value(v) * int(ph) + e * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME;
- return Value((r / GrainSize) * GrainSize); // Sign independent
+ return Value((mg_value(v) * int(ph) + e * int(PHASE_MIDGAME - ph)) / PHASE_MIDGAME);
}
// apply_weight() weights score v by score w trying to prevent overflow