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Introduce and use same_color_squares()

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No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2010-07-25 11:05:01 +01:00
parent a84e4b2049
commit 9b1d5bd534
4 changed files with 16 additions and 11 deletions
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18
src/endgame.cpp
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@@ -152,7 +152,7 @@ Value EvaluationFunction<KBNK>::apply(const Position& pos) const {
Square loserKSq = pos.king_square(weakerSide);
Square bishopSquare = pos.piece_list(strongerSide, BISHOP, 0);
if (square_color(bishopSquare) == BLACK)
if (same_color_squares(bishopSquare, SQ_A1))
{
winnerKSq = flop_square(winnerKSq);
loserKSq = flop_square(loserKSq);
@@ -398,7 +398,7 @@ ScaleFactor ScalingFunction<KBPsK>::apply(const Position& pos) const {
Square queeningSq = relative_square(strongerSide, make_square(pawnFile, RANK_8));
Square kingSq = pos.king_square(weakerSide);
if ( square_color(queeningSq) != square_color(bishopSq)
if ( !same_color_squares(queeningSq, bishopSq)
&& file_distance(square_file(kingSq), pawnFile) <= 1)
{
// The bishop has the wrong color, and the defending king is on the
@@ -675,12 +675,12 @@ ScaleFactor ScalingFunction<KBPKB>::apply(const Position& pos) const {
// Case 1: Defending king blocks the pawn, and cannot be driven away
if ( square_file(weakerKingSq) == square_file(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( square_color(weakerKingSq) != square_color(strongerBishopSq)
&& ( !same_color_squares(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_ZERO;
// Case 2: Opposite colored bishops
if (square_color(strongerBishopSq) != square_color(weakerBishopSq))
if (!same_color_squares(strongerBishopSq, weakerBishopSq))
{
// We assume that the position is drawn in the following three situations:
//
@@ -724,7 +724,7 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
Square wbsq = pos.piece_list(strongerSide, BISHOP, 0);
Square bbsq = pos.piece_list(weakerSide, BISHOP, 0);
if (square_color(wbsq) == square_color(bbsq))
if (same_color_squares(wbsq, bbsq))
// Not opposite-colored bishops, no scaling
return SCALE_FACTOR_NONE;
@@ -753,7 +753,7 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
// some square in the frontmost pawn's path.
if ( square_file(ksq) == square_file(blockSq1)
&& relative_rank(strongerSide, ksq) >= relative_rank(strongerSide, blockSq1)
&& square_color(ksq) != square_color(wbsq))
&& !same_color_squares(ksq, wbsq))
return SCALE_FACTOR_ZERO;
else
return SCALE_FACTOR_NONE;
@@ -763,14 +763,14 @@ ScaleFactor ScalingFunction<KBPPKB>::apply(const Position& pos) const {
// in front of the frontmost pawn's path, and the square diagonally behind
// this square on the file of the other pawn.
if ( ksq == blockSq1
&& square_color(ksq) != square_color(wbsq)
&& !same_color_squares(ksq, wbsq)
&& ( bbsq == blockSq2
|| (pos.attacks_from<BISHOP>(blockSq2) & pos.pieces(BISHOP, weakerSide))
|| rank_distance(r1, r2) >= 2))
return SCALE_FACTOR_ZERO;
else if ( ksq == blockSq2
&& square_color(ksq) != square_color(wbsq)
&& !same_color_squares(ksq, wbsq)
&& ( bbsq == blockSq1
|| (pos.attacks_from<BISHOP>(blockSq1) & pos.pieces(BISHOP, weakerSide))))
return SCALE_FACTOR_ZERO;
@@ -804,7 +804,7 @@ ScaleFactor ScalingFunction<KBPKN>::apply(const Position& pos) const {
if ( square_file(weakerKingSq) == square_file(pawnSq)
&& relative_rank(strongerSide, pawnSq) < relative_rank(strongerSide, weakerKingSq)
&& ( square_color(weakerKingSq) != square_color(strongerBishopSq)
&& ( !same_color_squares(weakerKingSq, strongerBishopSq)
|| relative_rank(strongerSide, weakerKingSq) <= RANK_6))
return SCALE_FACTOR_ZERO;