Fix isolated and backward pawns scoring

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index 5539b7a6faa660da7897c7caf43d0b5d662102bf..826fa13bfa85233cfe7931e4606e237ffa6bede8 100644 (file)
--- a/src/position.h
+++ b/src/position.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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -51,7 +51,7 @@
 ////
 
 /// FEN string for the initial position
-const std::string StartPosition = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+const std::string StartPositionFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
 
 /// Maximum number of plies per game (220 should be enough, because the
 /// maximum search depth is 100, and during position setup we reset the
@@ -68,11 +68,11 @@ const int MaxGameLength = 220;
 
 struct CheckInfo {
 
-    CheckInfo(const Position&);
+    explicit CheckInfo(const Position&);
 
-    Square ksq;
     Bitboard dcCandidates;
     Bitboard checkSq[8];
+    Square ksq;
 };
 
 /// Castle rights, encoded as bit fields
@@ -100,13 +100,13 @@ enum Phase {
 
 struct StateInfo {
   Key pawnKey, materialKey;
-  int castleRights, rule50, pliesFromNull;
+  int castleRights, rule50, gamePly, pliesFromNull;
   Square epSquare;
   Score value;
   Value npMaterial[2];
 
-  Key key;
   PieceType capture;
+  Key key;
   Bitboard checkersBB;
   StateInfo* previous;
 };
@@ -139,6 +139,9 @@ class Position {
   friend class MaterialInfo;
   friend class EndgameFunctions;
 
+  Position(); // No default or copy c'tor allowed
+  Position(const Position& pos);
+
 public:
   enum GamePhase {
       MidGame,
@@ -146,9 +149,9 @@ public:
   };
 
   // Constructors
-  Position() {}
-  Position(const Position& pos);
-  Position(const std::string& fen);
+  explicit Position(int threadID);
+  Position(const Position& pos, int threadID);
+  Position(const std::string& fen, int threadID);
 
   // Text input/output
   void from_fen(const std::string& fen);
@@ -156,7 +159,6 @@ public:
   void print(Move m = MOVE_NONE) const;
 
   // Copying
-  void copy(const Position& pos);
   void flipped_copy(const Position& pos);
 
   // The piece on a given square
@@ -224,17 +226,17 @@ public:
   bool move_is_passed_pawn_push(Move m) const;
   bool move_attacks_square(Move m, Square s) const;
 
+  // Piece captured with previous moves
+  PieceType captured_piece() const;
+
   // Information about pawns
   bool pawn_is_passed(Color c, Square s) const;
-  static bool pawn_is_passed(Bitboard theirPawns, Color c, Square s);
-  static bool pawn_is_isolated(Bitboard ourPawns, Square s);
-  static bool pawn_is_doubled(Bitboard ourPawns, Color c, Square s);
 
   // Weak squares
   bool square_is_weak(Square s, Color c) const;
 
   // Doing and undoing moves
-  void saveState();
+  void detach();
   void do_move(Move m, StateInfo& st);
   void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck);
   void undo_move(Move m);
@@ -249,13 +251,14 @@ public:
 
   // Accessing hash keys
   Key get_key() const;
+  Key get_exclusion_key() const;
   Key get_pawn_key() const;
   Key get_material_key() const;
 
   // Incremental evaluation
   Score value() const;
   Value non_pawn_material(Color c) const;
-  Score pst_delta(Piece piece, Square from, Square to) const;
+  static Score pst_delta(Piece piece, Square from, Square to);
 
   // Game termination checks
   bool is_mate() const;
@@ -271,6 +274,9 @@ public:
   bool opposite_colored_bishops() const;
   bool has_pawn_on_7th(Color c) const;
 
+  // Current thread ID searching on the position
+  int thread() const;
+
   // Reset the gamePly variable to 0
   void reset_game_ply();
 
@@ -290,7 +296,7 @@ private:
   void allow_ooo(Color c);
 
   // Helper functions for doing and undoing moves
-  void do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep);
+  void do_capture_move(Key& key, PieceType capture, Color them, Square to, bool ep);
   void do_castle_move(Move m);
   void undo_castle_move(Move m);
   void find_checkers();
@@ -304,7 +310,7 @@ private:
   Key compute_material_key() const;
 
   // Computing incremental evaluation scores and material counts
-  Score pst(Color c, PieceType pt, Square s) const;
+  static Score pst(Color c, PieceType pt, Square s);
   Score compute_value() const;
   Value compute_non_pawn_material(Color c) const;
 
@@ -323,20 +329,20 @@ private:
 
   // Other info
   Color sideToMove;
-  int gamePly;
   Key history[MaxGameLength];
-  File initialKFile, initialKRFile, initialQRFile;
+  int castleRightsMask[64];
   StateInfo startState;
+  File initialKFile, initialKRFile, initialQRFile;
+  int threadID;
   StateInfo* st;
 
   // Static variables
-  static int castleRightsMask[64];
   static Key zobrist[2][8][64];
   static Key zobEp[64];
   static Key zobCastle[16];
-  static Key zobMaterial[2][8][16];
   static Key zobSideToMove;
   static Score PieceSquareTable[16][64];
+  static Key zobExclusion;
 };
 
 
@@ -408,8 +414,8 @@ inline int Position::piece_count(Color c, PieceType pt) const {
   return pieceCount[c][pt];
 }
 
-inline Square Position::piece_list(Color c, PieceType pt, int index) const {
-  return pieceList[c][pt][index];
+inline Square Position::piece_list(Color c, PieceType pt, int idx) const {
+  return pieceList[c][pt][idx];
 }
 
 inline const Square* Position::piece_list_begin(Color c, PieceType pt) const {
@@ -481,26 +487,18 @@ inline bool Position::pawn_is_passed(Color c, Square s) const {
   return !(pieces(PAWN, opposite_color(c)) & passed_pawn_mask(c, s));
 }
 
-inline bool Position::pawn_is_passed(Bitboard theirPawns, Color c, Square s) {
-  return !(theirPawns & passed_pawn_mask(c, s));
-}
-
-inline bool Position::pawn_is_isolated(Bitboard ourPawns, Square s) {
-  return !(ourPawns & neighboring_files_bb(s));
-}
-
-inline bool Position::pawn_is_doubled(Bitboard ourPawns, Color c, Square s) {
-  return ourPawns & squares_behind(c, s);
-}
-
 inline bool Position::square_is_weak(Square s, Color c) const {
-  return !(pieces(PAWN, c) & outpost_mask(opposite_color(c), s));
+  return !(pieces(PAWN, opposite_color(c)) & attack_span_mask(c, s));
 }
 
 inline Key Position::get_key() const {
   return st->key;
 }
 
+inline Key Position::get_exclusion_key() const {
+  return st->key ^ zobExclusion;
+}
+
 inline Key Position::get_pawn_key() const {
   return st->pawnKey;
 }
@@ -509,11 +507,11 @@ inline Key Position::get_material_key() const {
   return st->materialKey;
 }
 
-inline Score Position::pst(Color c, PieceType pt, Square s) const {
+inline Score Position::pst(Color c, PieceType pt, Square s) {
   return PieceSquareTable[piece_of_color_and_type(c, pt)][s];
 }
 
-inline Score Position::pst_delta(Piece piece, Square from, Square to) const {
+inline Score Position::pst_delta(Piece piece, Square from, Square to) {
   return PieceSquareTable[piece][to] - PieceSquareTable[piece][from];
 }
 
@@ -561,4 +559,12 @@ inline bool Position::move_is_capture_or_promotion(Move m) const {
   return (m & (0x1F << 12)) ? !move_is_castle(m) : !square_is_empty(move_to(m));
 }
 
+inline PieceType Position::captured_piece() const {
+  return st->capture;
+}
+
+inline int Position::thread() const {
+  return threadID;
+}
+
 #endif // !defined(POSITION_H_INCLUDED)