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#include <stdio.h>
#include "bitboard.h"
/* Print bitboard on screen in the same way squares appear in memory
* (i.e the board is actually flipped along X) */
void printBitboard(Bitboard bb) {
for (U64 index = 0; index < 64; index++) {
printf("%c", (bb >> index) & 1 ? '1' : '.');
if ((index + 1) % 8 == 0) printf("\n");
}
printf("\n\n");
}
/* Return bitboard cardinality, aka number of elements in the set */
inline int popCount(Bitboard bb){
if (bb == 0) return 0;
return popCount(bb >> 1) + (bb & 1);
}
/* Return Bitboard with only Least Single Bit */
inline Bitboard ls1b(Bitboard bb) {
return bb & -bb;
}
/* Log base 2 (aka Trailing Zero Count)
* Only works for SINGLE Bitboards
* Useful for calculating bit-index of LS1B */
inline int bitscan(Bitboard bb) {
return popCount(ls1b(bb) - 1);
}
/* Bitscan forward with LS1B reset */
inline int bitscanAndReset(Bitboard* bb) {
int idx = bitscan(*bb);
*bb &= *bb - 1;
return idx;
}
/* These 4 blindly copied from chessprogramming.org TODO: rewrite */
U64 rankMask(enumSquare sq) {
return C64(0xff) << (sq & 56);
}
U64 fileMask(enumSquare sq) {
return C64(0x0101010101010101) << (sq & 7);
}
U64 diagonalMask(enumSquare sq) {
const U64 maindia = C64(0x8040201008040201);
int diag =8*(sq & 7) - (sq & 56);
int nort = -diag & ( diag >> 31);
int sout = diag & (-diag >> 31);
return (maindia >> sout) << nort;
}
U64 antiDiagMask(enumSquare sq) {
const U64 maindia = C64(0x0102040810204080);
int diag =56- 8*(sq&7) - (sq&56);
int nort = -diag & ( diag >> 31);
int sout = diag & (-diag >> 31);
return (maindia >> sout) << nort;
}
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