droidfish/DroidFish/jni/stockfish/move.cpp
2011-11-12 19:44:06 +00:00

259 lines
6.9 KiB
C++

/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <cassert>
#include <cstring>
#include <iomanip>
#include <string>
#include <sstream>
#include "move.h"
#include "movegen.h"
#include "search.h"
using std::string;
namespace {
const string time_string(int milliseconds);
const string score_string(Value v);
}
/// move_to_uci() converts a move to a string in coordinate notation
/// (g1f3, a7a8q, etc.). The only special case is castling moves, where we
/// print in the e1g1 notation in normal chess mode, and in e1h1 notation in
/// Chess960 mode.
const string move_to_uci(Move m, bool chess960) {
Square from = move_from(m);
Square to = move_to(m);
string promotion;
if (m == MOVE_NONE)
return "(none)";
if (m == MOVE_NULL)
return "0000";
if (move_is_short_castle(m) && !chess960)
return from == SQ_E1 ? "e1g1" : "e8g8";
if (move_is_long_castle(m) && !chess960)
return from == SQ_E1 ? "e1c1" : "e8c8";
if (move_is_promotion(m))
promotion = char(tolower(piece_type_to_char(move_promotion_piece(m))));
return square_to_string(from) + square_to_string(to) + promotion;
}
/// move_from_uci() takes a position and a string representing a move in
/// simple coordinate notation and returns an equivalent Move if any.
/// Moves are guaranteed to be legal.
Move move_from_uci(const Position& pos, const string& str) {
MoveStack mlist[MAX_MOVES];
MoveStack* last = generate<MV_LEGAL>(pos, mlist);
for (MoveStack* cur = mlist; cur != last; cur++)
if (str == move_to_uci(cur->move, pos.is_chess960()))
return cur->move;
return MOVE_NONE;
}
/// move_to_san() takes a position and a move as input, where it is assumed
/// that the move is a legal move from the position. The return value is
/// a string containing the move in short algebraic notation.
const string move_to_san(Position& pos, Move m) {
assert(pos.is_ok());
assert(move_is_ok(m));
MoveStack mlist[MAX_MOVES];
Square from = move_from(m);
Square to = move_to(m);
PieceType pt = pos.type_of_piece_on(from);
string san;
if (m == MOVE_NONE)
return "(none)";
if (m == MOVE_NULL)
return "(null)";
if (move_is_long_castle(m))
san = "O-O-O";
else if (move_is_short_castle(m))
san = "O-O";
else
{
if (pt != PAWN)
{
san = piece_type_to_char(pt);
// Collect all legal moves of piece type 'pt' with destination 'to'
MoveStack* last = generate<MV_LEGAL>(pos, mlist);
int f = 0, r = 0;
for (MoveStack* cur = mlist; cur != last; cur++)
if ( move_to(cur->move) == to
&& pos.type_of_piece_on(move_from(cur->move)) == pt)
{
if (square_file(move_from(cur->move)) == square_file(from))
f++;
if (square_rank(move_from(cur->move)) == square_rank(from))
r++;
}
assert(f > 0 && r > 0);
// Disambiguation if we have more then one piece with destination 'to'
if (f == 1 && r > 1)
san += file_to_char(square_file(from));
else if (f > 1 && r == 1)
san += rank_to_char(square_rank(from));
else if (f > 1 && r > 1)
san += square_to_string(from);
}
if (pos.move_is_capture(m))
{
if (pt == PAWN)
san += file_to_char(square_file(from));
san += 'x';
}
san += square_to_string(to);
if (move_is_promotion(m))
{
san += '=';
san += piece_type_to_char(move_promotion_piece(m));
}
}
// The move gives check? We don't use pos.move_gives_check() here
// because we need to test for a mate after the move is done.
StateInfo st;
pos.do_move(m, st);
if (pos.in_check())
san += pos.is_mate() ? "#" : "+";
pos.undo_move(m);
return san;
}
/// pretty_pv() creates a human-readable string from a position and a PV.
/// It is used to write search information to the log file (which is created
/// when the UCI parameter "Use Search Log" is "true").
const string pretty_pv(Position& pos, int depth, Value score, int time, Move pv[]) {
const int64_t K = 1000;
const int64_t M = 1000000;
const int startColumn = 28;
const size_t maxLength = 80 - startColumn;
const string lf = string("\n") + string(startColumn, ' ');
StateInfo state[PLY_MAX_PLUS_2], *st = state;
Move* m = pv;
string san;
std::stringstream s;
size_t length = 0;
// First print depth, score, time and searched nodes...
s << std::setw(2) << depth
<< std::setw(8) << score_string(score)
<< std::setw(8) << time_string(time);
if (pos.nodes_searched() < M)
s << std::setw(8) << pos.nodes_searched() / 1 << " ";
else if (pos.nodes_searched() < K * M)
s << std::setw(7) << pos.nodes_searched() / K << "K ";
else
s << std::setw(7) << pos.nodes_searched() / M << "M ";
// ...then print the full PV line in short algebraic notation
while (*m != MOVE_NONE)
{
san = move_to_san(pos, *m);
length += san.length() + 1;
if (length > maxLength)
{
length = san.length() + 1;
s << lf;
}
s << san << ' ';
pos.do_move(*m++, *st++);
}
// Restore original position before to leave
while (m != pv) pos.undo_move(*--m);
return s.str();
}
namespace {
const string time_string(int millisecs) {
const int MSecMinute = 1000 * 60;
const int MSecHour = 1000 * 60 * 60;
int hours = millisecs / MSecHour;
int minutes = (millisecs % MSecHour) / MSecMinute;
int seconds = ((millisecs % MSecHour) % MSecMinute) / 1000;
std::stringstream s;
if (hours)
s << hours << ':';
s << std::setfill('0') << std::setw(2) << minutes << ':' << std::setw(2) << seconds;
return s.str();
}
const string score_string(Value v) {
std::stringstream s;
if (v >= VALUE_MATE - 200)
s << "#" << (VALUE_MATE - v + 1) / 2;
else if (v <= -VALUE_MATE + 200)
s << "-#" << (VALUE_MATE + v) / 2;
else
s << std::setprecision(2) << std::fixed << std::showpos << float(v) / PawnValueMidgame;
return s.str();
}
}