/* Glaurung, a UCI chess playing engine. Copyright (C) 2004-2008 Tord Romstad Glaurung 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. Glaurung 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 . */ //// //// Includes //// #include #include #include "value.h" //// //// Functions //// /// value_to_tt() adjusts a mate score from "plies to mate from the root" to /// "plies to mate from the current ply". Non-mate scores are unchanged. /// The function is called before storing a value to the transposition table. Value value_to_tt(Value v, int ply) { if(v >= value_mate_in(100)) return v + ply; else if(v <= value_mated_in(100)) return v - ply; else return v; } /// value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score /// from the transposition table to a mate score corrected for the current /// ply depth. Value value_from_tt(Value v, int ply) { if(v >= value_mate_in(100)) return v - ply; else if(v <= value_mated_in(100)) return v + ply; else return v; } /// value_to_centipawns() converts a value from Glaurung's somewhat unusual /// scale of pawn = 256 to the more conventional pawn = 100. int value_to_centipawns(Value v) { return (int(v) * 100) / int(PawnValueMidgame); } /// value_from_centipawns() converts a centipawn value to Glaurung's internal /// evaluation scale. It's used when reading the values of UCI options /// containing material values (e.g. futility pruning margins). Value value_from_centipawns(int cp) { return Value((cp * 256) / 100); } /// value_to_string() converts a value to a string suitable for use with the /// UCI protocol. const std::string value_to_string(Value v) { std::stringstream s; if(abs(v) < VALUE_MATE - 200) s << "cp " << value_to_centipawns(v); else { s << "mate "; if(v > 0) s << (VALUE_MATE - v + 1) / 2; else s << -(VALUE_MATE + v) / 2; } return s.str(); }