Rewrite unstoppable pawns evaluation

[stockfish] / src / pawns.h

diff --git a/src/pawns.h b/src/pawns.h
index 0376ce617f098e7c151dd45cf6816640936f11d8..0098a963db224a478d74eed4164d24acb5ffebad 100644 (file)
--- a/src/pawns.h
+++ b/src/pawns.h
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2013 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
@@ -17,38 +17,41 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#if !defined(PAWNS_H_INCLUDED)
+#ifndef PAWNS_H_INCLUDED
 #define PAWNS_H_INCLUDED
 
 #include "misc.h"
 #include "position.h"
 #include "types.h"
 
-const int PawnTableSize = 16384;
+namespace Pawns {
 
-/// PawnEntry is a class which contains various information about a pawn
-/// structure. Currently, it only includes a middle game and an end game
-/// pawn structure evaluation, and a bitboard of passed pawns. We may want
-/// to add further information in the future. A lookup to the pawn hash
-/// table (performed by calling the probe method in a PawnTable object)
-/// returns a pointer to a PawnEntry object.
+/// Pawns::Entry contains various information about a pawn structure. Currently,
+/// it only includes a middle game and end game pawn structure evaluation, and a
+/// bitboard of passed pawns. We may want to add further information in the future.
+/// A lookup to the pawn hash table (performed by calling the probe function)
+/// returns a pointer to an Entry object.
 
-class PawnEntry {
+struct Entry {
 
-  friend struct PawnTable;
+  Score pawns_value() const { return value; }
+  Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; }
+  Bitboard passed_pawns(Color c) const { return passedPawns[c]; }
+  Bitboard candidate_pawns(Color c) const { return candidatePawns[c]; }
+  int pawns_on_same_color_squares(Color c, Square s) const { return pawnsOnSquares[c][!!(DarkSquares & s)]; }
+  int semiopen(Color c, File f) const { return semiopenFiles[c] & (1 << int(f)); }
+  int semiopen_on_side(Color c, File f, bool left) const {
 
-public:
-  Score pawns_value() const;
-  Bitboard pawn_attacks(Color c) const;
-  Bitboard passed_pawns(Color c) const;
-  int file_is_half_open(Color c, File f) const;
-  int has_open_file_to_left(Color c, File f) const;
-  int has_open_file_to_right(Color c, File f) const;
+    return semiopenFiles[c] & (left ? ((1 << int(f)) - 1) : ~((1 << int(f+1)) - 1));
+  }
 
   template<Color Us>
-  Score king_safety(const Position& pos, Square ksq);
+  Score king_safety(const Position& pos, Square ksq)  {
+
+    return kingSquares[Us] == ksq && castleRights[Us] == pos.can_castle(Us)
+         ? kingSafety[Us] : update_safety<Us>(pos, ksq);
+  }
 
-private:
   template<Color Us>
   Score update_safety(const Position& pos, Square ksq);
 
@@ -56,57 +59,22 @@ private:
   Value shelter_storm(const Position& pos, Square ksq);
 
   Key key;
-  Bitboard passedPawns[2];
-  Bitboard pawnAttacks[2];
-  Square kingSquares[2];
+  Bitboard passedPawns[COLOR_NB];
+  Bitboard candidatePawns[COLOR_NB];
+  Bitboard pawnAttacks[COLOR_NB];
+  Square kingSquares[COLOR_NB];
+  int minKPdistance[COLOR_NB];
+  int castleRights[COLOR_NB];
   Score value;
-  int halfOpenFiles[2];
-  Score kingSafety[2];
-};
-
-
-/// The PawnTable class represents a pawn hash table. The most important
-/// method is probe, which returns a pointer to a PawnEntry object.
-
-struct PawnTable {
-
-  PawnEntry* probe(const Position& pos);
-
-  template<Color Us>
-  static Score evaluate_pawns(const Position& pos, Bitboard ourPawns,
-                              Bitboard theirPawns, PawnEntry* e);
-
-  HashTable<PawnEntry, PawnTableSize> entries;
+  int semiopenFiles[COLOR_NB];
+  Score kingSafety[COLOR_NB];
+  int pawnsOnSquares[COLOR_NB][COLOR_NB];
 };
 
+typedef HashTable<Entry, 16384> Table;
 
-inline Score PawnEntry::pawns_value() const {
-  return value;
-}
-
-inline Bitboard PawnEntry::pawn_attacks(Color c) const {
-  return pawnAttacks[c];
-}
-
-inline Bitboard PawnEntry::passed_pawns(Color c) const {
-  return passedPawns[c];
-}
-
-inline int PawnEntry::file_is_half_open(Color c, File f) const {
-  return halfOpenFiles[c] & (1 << int(f));
-}
-
-inline int PawnEntry::has_open_file_to_left(Color c, File f) const {
-  return halfOpenFiles[c] & ((1 << int(f)) - 1);
-}
-
-inline int PawnEntry::has_open_file_to_right(Color c, File f) const {
-  return halfOpenFiles[c] & ~((1 << int(f+1)) - 1);
-}
+Entry* probe(const Position& pos, Table& entries);
 
-template<Color Us>
-inline Score PawnEntry::king_safety(const Position& pos, Square ksq) {
-  return kingSquares[Us] == ksq ? kingSafety[Us] : update_safety<Us>(pos, ksq);
 }
 
-#endif // !defined(PAWNS_H_INCLUDED)
+#endif // #ifndef PAWNS_H_INCLUDED