+extern Bitboard RMasks[SQUARE_NB];
+extern Bitboard RMagics[SQUARE_NB];
+extern Bitboard* RAttacks[SQUARE_NB];
+extern unsigned RShifts[SQUARE_NB];
+
+extern Bitboard BMasks[SQUARE_NB];
+extern Bitboard BMagics[SQUARE_NB];
+extern Bitboard* BAttacks[SQUARE_NB];
+extern unsigned BShifts[SQUARE_NB];
+
+extern Bitboard SquareBB[SQUARE_NB];
+extern Bitboard FileBB[FILE_NB];
+extern Bitboard RankBB[RANK_NB];
+extern Bitboard AdjacentFilesBB[FILE_NB];
+extern Bitboard InFrontBB[COLOR_NB][RANK_NB];
+extern Bitboard StepAttacksBB[PIECE_NB][SQUARE_NB];
+extern Bitboard BetweenBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard LineBB[SQUARE_NB][SQUARE_NB];
+extern Bitboard DistanceRingsBB[SQUARE_NB][8];
+extern Bitboard ForwardBB[COLOR_NB][SQUARE_NB];
+extern Bitboard PassedPawnMask[COLOR_NB][SQUARE_NB];
+extern Bitboard PawnAttackSpan[COLOR_NB][SQUARE_NB];
+extern Bitboard PseudoAttacks[PIECE_TYPE_NB][SQUARE_NB];
+
+extern int SquareDistance[SQUARE_NB][SQUARE_NB];
+
+const Bitboard DarkSquares = 0xAA55AA55AA55AA55ULL;