/*
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
//// Variables
////
-int Position::castleRightsMask[64];
-
Key Position::zobrist[2][8][64];
Key Position::zobEp[64];
Key Position::zobCastle[16];
checkSq[KING] = EmptyBoardBB;
}
+
+/// Position c'tors. Here we always create a slower but safer copy of
+/// the original position or the FEN string, we want the new born Position
+/// object do not depend on any external data. Instead if we know what we
+/// are doing and we need speed we can create a position with default
+/// c'tor Position() and then use just fast_copy().
+
+Position::Position() {}
+
Position::Position(const Position& pos) {
- copy(pos);
+
+ memcpy(this, &pos, sizeof(Position));
+ detach(); // Always detach() in copy c'tor to avoid surprises
}
Position::Position(const string& fen) {
+
from_fen(fen);
}
+/// Position::detach() copies the content of the current state and castling
+/// masks inside the position itself. This is needed when the st pointee could
+/// become stale, as example because the caller is about to going out of scope.
+
+void Position::detach() {
+
+ startState = *st;
+ st = &startState;
+ st->previous = NULL; // as a safe guard
+}
+
+
/// Position::from_fen() initializes the position object with the given FEN
/// string. This function is not very robust - make sure that input FENs are
/// correct (this is assumed to be the responsibility of the GUI).
std::cout << std::endl;
if (m != MOVE_NONE)
{
+ Position p(*this);
string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
- std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl;
+ std::cout << "Move is: " << col << move_to_san(p, m) << std::endl;
}
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
}
-/// Position::copy() creates a copy of the input position.
-
-void Position::copy(const Position& pos) {
-
- memcpy(this, &pos, sizeof(Position));
- saveState(); // detach and copy state info
-}
-
-
/// Position:hidden_checkers<>() returns a bitboard of all pinned (against the
/// king) pieces for the given color and for the given pinner type. Or, when
/// template parameter FindPinned is false, the pieces of the given color
}
-/// Position::saveState() copies the content of the current state
-/// inside startState and makes st point to it. This is needed
-/// when the st pointee could become stale, as example because
-/// the caller is about to going out of scope.
-
-void Position::saveState() {
-
- startState = *st;
- st = &startState;
- st->previous = NULL; // as a safe guard
-}
-
-
/// Position::clear() erases the position object to a pristine state, with an
/// empty board, white to move, and no castling rights.
/// Position::is_draw() tests whether the position is drawn by material,
/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
+// FIXME: Currently we are not handling 50 move rule correctly when in check
bool Position::is_draw() const {
return true;
// Draw by repetition?
- for (int i = 2; i < Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
+ for (int i = 4; i <= Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
if (history[gamePly - i] == st->key)
return true;