#include "material.h"
#include "pawns.h"
#include "thread.h"
-#include "ucioption.h"
namespace {
assert(target & (pos.pieces(C) ^ pos.pieces(C, KING)));
- PieceType pt;
- for (pt = QUEEN; !(target & pos.pieces(C, pt)); --pt) {}
- return pt;
+ for (PieceType pt = QUEEN; pt > PAWN; --pt)
+ if (target & pos.pieces(C, pt))
+ return pt;
+
+ return PAWN;
}
if ( ei.mi->game_phase() < PHASE_MIDGAME
&& (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
{
- if (pos.opposite_bishops()) {
- // Ignoring any pawns, do both sides only have a single bishop and no
- // other pieces?
+ if (pos.opposite_bishops())
+ {
+ // Endgame with opposite-colored bishops and no other pieces (ignoring pawns)
+ // is almost a draw, in case of KBP vs KB is even more a draw.
if ( pos.non_pawn_material(WHITE) == BishopValueMg
&& pos.non_pawn_material(BLACK) == BishopValueMg)
- {
- // Check for KBP vs KB with only a single pawn that is almost
- // certainly a draw or at least two pawns.
- bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
- sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
- }
+ sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(32) : ScaleFactor(8);
+
+ // Endgame with opposite-colored bishops, but also other pieces. Still
+ // a bit drawish, but not as drawish as with only the two bishops.
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 / SCALE_FACTOR_NORMAL);
- } else if ( abs(eg_value(score)) <= BishopValueEg
- && ei.pi->pawn_span(strongSide) <= 1
- && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide))) {
- // Endings where weaker side can be place his king in front of the opponent's pawns are drawish.
- sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]);
}
+ // Endings where weaker side can place his king in front of the opponent's
+ // pawns are drawish.
+ else if ( abs(eg_value(score)) <= BishopValueEg
+ && ei.pi->pawn_span(strongSide) <= 1
+ && !pos.pawn_passed(~strongSide, pos.king_square(~strongSide)))
+ sf = ScaleFactor(ScalePawnSpan[ei.pi->pawn_span(strongSide)]);
}
// Interpolate between a middlegame and a (scaled by 'sf') endgame score
}
- /// init() computes evaluation weights from the corresponding UCI parameters
- /// and setup king tables.
+ /// init() computes evaluation weights.
void init() {