mirror of
https://github.com/sockspls/badfish
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87 lines
2.1 KiB
C++
87 lines
2.1 KiB
C++
/*
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Stockfish, a UCI chess playing engine derived from Glaurung 2.1
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Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
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Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
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Stockfish is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Stockfish is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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////
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//// Includes
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////
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#include "direction.h"
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#include "square.h"
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////
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//// Local definitions
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////
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namespace {
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const SquareDelta directionToDelta[] = {
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DELTA_E, DELTA_W, DELTA_N, DELTA_S, DELTA_NE, DELTA_SW, DELTA_NW, DELTA_SE
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};
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bool reachable(Square orig, Square dest, SignedDirection dir) {
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SquareDelta delta = directionToDelta[dir];
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Square from = orig;
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Square to = from + delta;
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while (to != dest && square_distance(to, from) == 1 && square_is_ok(to))
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{
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from = to;
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to += delta;
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}
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return (to == dest && square_distance(from, to) == 1);
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}
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}
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////
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//// Variables
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////
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uint8_t DirectionTable[64][64];
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uint8_t SignedDirectionTable[64][64];
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////
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//// Functions
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////
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void init_direction_table() {
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for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++)
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for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++)
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{
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DirectionTable[s1][s2] = uint8_t(DIR_NONE);
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SignedDirectionTable[s1][s2] = uint8_t(SIGNED_DIR_NONE);
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if (s1 == s2)
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continue;
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for (SignedDirection d = SIGNED_DIR_E; d != SIGNED_DIR_NONE; d++)
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{
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if (reachable(s1, s2, d))
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{
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SignedDirectionTable[s1][s2] = uint8_t(d);
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DirectionTable[s1][s2] = uint8_t(d / 2);
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break;
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}
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}
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}
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}
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