2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #if !defined(SQUARE_H_INCLUDED)
22 #define SQUARE_H_INCLUDED
28 #include <cstdlib> // for abs()
40 SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_F1, SQ_G1, SQ_H1,
41 SQ_A2, SQ_B2, SQ_C2, SQ_D2, SQ_E2, SQ_F2, SQ_G2, SQ_H2,
42 SQ_A3, SQ_B3, SQ_C3, SQ_D3, SQ_E3, SQ_F3, SQ_G3, SQ_H3,
43 SQ_A4, SQ_B4, SQ_C4, SQ_D4, SQ_E4, SQ_F4, SQ_G4, SQ_H4,
44 SQ_A5, SQ_B5, SQ_C5, SQ_D5, SQ_E5, SQ_F5, SQ_G5, SQ_H5,
45 SQ_A6, SQ_B6, SQ_C6, SQ_D6, SQ_E6, SQ_F6, SQ_G6, SQ_H6,
46 SQ_A7, SQ_B7, SQ_C7, SQ_D7, SQ_E7, SQ_F7, SQ_G7, SQ_H7,
47 SQ_A8, SQ_B8, SQ_C8, SQ_D8, SQ_E8, SQ_F8, SQ_G8, SQ_H8,
52 FILE_A, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H, FILE_NONE
56 RANK_1, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8, RANK_NONE
61 DELTA_N = 8, DELTA_E = 1, DELTA_S = -8, DELTA_W = -1,
63 DELTA_NN = DELTA_N + DELTA_N,
64 DELTA_NE = DELTA_N + DELTA_E,
65 DELTA_SE = DELTA_S + DELTA_E,
66 DELTA_SS = DELTA_S + DELTA_S,
67 DELTA_SW = DELTA_S + DELTA_W,
68 DELTA_NW = DELTA_N + DELTA_W,
72 DIR_E = 0, DIR_N = 1, DIR_NE = 2, DIR_NW = 3, DIR_NONE = 4
75 enum SignedDirection {
76 SIGNED_DIR_E = 0, SIGNED_DIR_W = 1,
77 SIGNED_DIR_N = 2, SIGNED_DIR_S = 3,
78 SIGNED_DIR_NE = 4, SIGNED_DIR_SW = 5,
79 SIGNED_DIR_NW = 6, SIGNED_DIR_SE = 7,
83 ENABLE_OPERATORS_ON(Square);
84 ENABLE_OPERATORS_ON(File);
85 ENABLE_OPERATORS_ON(Rank);
86 ENABLE_OPERATORS_ON(SquareDelta);
87 ENABLE_OPERATORS_ON(SignedDirection);
94 const int FlipMask = 56;
95 const int FlopMask = 7;
97 extern uint8_t DirectionTable[64][64];
98 extern uint8_t SignedDirectionTable[64][64];
102 //// Inline functions
105 inline Square operator+ (Square x, SquareDelta i) { return x + Square(i); }
106 inline void operator+= (Square& x, SquareDelta i) { x = x + Square(i); }
107 inline Square operator- (Square x, SquareDelta i) { return x - Square(i); }
108 inline void operator-= (Square& x, SquareDelta i) { x = x - Square(i); }
110 inline Square make_square(File f, Rank r) {
111 return Square(int(f) | (int(r) << 3));
114 inline File square_file(Square s) {
115 return File(int(s) & 7);
118 inline Rank square_rank(Square s) {
119 return Rank(int(s) >> 3);
122 inline Square flip_square(Square s) {
123 return Square(int(s) ^ FlipMask);
126 inline Square flop_square(Square s) {
127 return Square(int(s) ^ FlopMask);
130 inline Square relative_square(Color c, Square s) {
131 return Square(int(s) ^ (int(c) * FlipMask));
134 inline Rank relative_rank(Color c, Square s) {
135 return square_rank(relative_square(c, s));
138 inline SquareColor square_color(Square s) {
139 return SquareColor((int(square_file(s)) + int(square_rank(s))) & 1);
142 inline bool same_color_squares(Square s1, Square s2) {
143 int s = int(s1) ^ int(s2);
144 return (((s >> 3) ^ s) & 1) == 0;
147 inline int file_distance(File f1, File f2) {
148 return abs(int(f1) - int(f2));
151 inline int file_distance(Square s1, Square s2) {
152 return file_distance(square_file(s1), square_file(s2));
155 inline int rank_distance(Rank r1, Rank r2) {
156 return abs(int(r1) - int(r2));
159 inline int rank_distance(Square s1, Square s2) {
160 return rank_distance(square_rank(s1), square_rank(s2));
163 inline int square_distance(Square s1, Square s2) {
164 return Max(file_distance(s1, s2), rank_distance(s1, s2));
167 inline File file_from_char(char c) {
168 return File(c - 'a') + FILE_A;
171 inline char file_to_char(File f) {
172 return char(f - FILE_A + int('a'));
175 inline Rank rank_from_char(char c) {
176 return Rank(c - '1') + RANK_1;
179 inline char rank_to_char(Rank r) {
180 return char(r - RANK_1 + int('1'));
183 inline const std::string square_to_string(Square s) {
184 return std::string(1, file_to_char(square_file(s)))
185 + std::string(1, rank_to_char(square_rank(s)));
188 inline bool file_is_ok(File f) {
189 return f >= FILE_A && f <= FILE_H;
192 inline bool rank_is_ok(Rank r) {
193 return r >= RANK_1 && r <= RANK_8;
196 inline bool square_is_ok(Square s) {
197 return file_is_ok(square_file(s)) && rank_is_ok(square_rank(s));
200 inline Direction direction_between_squares(Square s1, Square s2) {
201 return Direction(DirectionTable[s1][s2]);
204 inline int direction_is_diagonal(Square s1, Square s2) {
205 return DirectionTable[s1][s2] & 2;
208 inline bool direction_is_straight(Square s1, Square s2) {
209 return DirectionTable[s1][s2] < 2;
216 extern void init_direction_table();
218 #endif // !defined(SQUARE_H_INCLUDED)