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, DELTA_NONE = 0,
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
71 ENABLE_OPERATORS_ON(Square);
72 ENABLE_OPERATORS_ON(File);
73 ENABLE_OPERATORS_ON(Rank);
74 ENABLE_OPERATORS_ON(SquareDelta);
81 const int FlipMask = 56;
82 const int FlopMask = 7;
84 extern int8_t DirectionTable[64][64];
91 inline Square operator+ (Square x, SquareDelta i) { return x + Square(i); }
92 inline void operator+= (Square& x, SquareDelta i) { x = x + Square(i); }
93 inline Square operator- (Square x, SquareDelta i) { return x - Square(i); }
94 inline void operator-= (Square& x, SquareDelta i) { x = x - Square(i); }
96 inline Square make_square(File f, Rank r) {
97 return Square(int(f) | (int(r) << 3));
100 inline File square_file(Square s) {
101 return File(int(s) & 7);
104 inline Rank square_rank(Square s) {
105 return Rank(int(s) >> 3);
108 inline Square flip_square(Square s) {
109 return Square(int(s) ^ FlipMask);
112 inline Square flop_square(Square s) {
113 return Square(int(s) ^ FlopMask);
116 inline Square relative_square(Color c, Square s) {
117 return Square(int(s) ^ (int(c) * FlipMask));
120 inline Rank relative_rank(Color c, Square s) {
121 return square_rank(relative_square(c, s));
124 inline SquareColor square_color(Square s) {
125 return SquareColor((int(square_file(s)) + int(square_rank(s))) & 1);
128 inline bool same_color_squares(Square s1, Square s2) {
129 int s = int(s1) ^ int(s2);
130 return (((s >> 3) ^ s) & 1) == 0;
133 inline int file_distance(File f1, File f2) {
134 return abs(int(f1) - int(f2));
137 inline int file_distance(Square s1, Square s2) {
138 return file_distance(square_file(s1), square_file(s2));
141 inline int rank_distance(Rank r1, Rank r2) {
142 return abs(int(r1) - int(r2));
145 inline int rank_distance(Square s1, Square s2) {
146 return rank_distance(square_rank(s1), square_rank(s2));
149 inline int square_distance(Square s1, Square s2) {
150 return Max(file_distance(s1, s2), rank_distance(s1, s2));
153 inline File file_from_char(char c) {
154 return File(c - 'a') + FILE_A;
157 inline char file_to_char(File f) {
158 return char(f - FILE_A + int('a'));
161 inline Rank rank_from_char(char c) {
162 return Rank(c - '1') + RANK_1;
165 inline char rank_to_char(Rank r) {
166 return char(r - RANK_1 + int('1'));
169 inline const std::string square_to_string(Square s) {
170 return std::string(1, file_to_char(square_file(s)))
171 + std::string(1, rank_to_char(square_rank(s)));
174 inline bool file_is_ok(File f) {
175 return f >= FILE_A && f <= FILE_H;
178 inline bool rank_is_ok(Rank r) {
179 return r >= RANK_1 && r <= RANK_8;
182 inline bool square_is_ok(Square s) {
183 return file_is_ok(square_file(s)) && rank_is_ok(square_rank(s));
186 inline bool squares_aligned(Square s1, Square s2, Square s3) {
187 return DirectionTable[s1][s2] != DELTA_NONE
188 && abs(DirectionTable[s1][s2]) == abs(DirectionTable[s2][s3]);
191 inline bool direction_is_straight(Square s1, Square s2) {
192 return abs(DirectionTable[s1][s2]) == DELTA_N
193 || abs(DirectionTable[s1][s2]) == DELTA_E;
200 extern void init_direction_table();
202 #endif // !defined(SQUARE_H_INCLUDED)