[BitBoard] Add bishop and pawn methods

BitBoard.cpp

@@ -25,9 +25,6 @@ std::ostream &operator<<(std::ostream &os, const BitBoard &board) {
     return os;
 }
 
-BitBoard BitBoard::getRank(int r) {
-    return (genShift(1ULL, (r + 1) * 8) - 1) & genShift(~1ULL, r * 8 - 1);
-}
 BitBoard BitBoard::genShift(BitBoard x, const int s) {
     return (s < 0) ? (x >> -s) : (s > 63) ? x : (x << s);
 }
@@ -58,5 +55,35 @@ BitBoard BitBoard::kingAttacks(const BitBoard bb) {
     result ^= bb;
 
     return result;
+}
 
+BitBoard BitBoard::bishopAttacks(BitBoard bishops, BitBoard empty) {
+    BitBoard result = 0;
+    BitBoard diag1 = bishops;
+    BitBoard diag2 = bishops;
+    empty ^= bishops;
+
+    for (int i = 0; i < 7; i++) {
+        result |= (diag1 | diag2);
+        diag1 = (diag1.northWest() | diag1.southEast()) & empty;
+        diag2 = (diag2.northEast() | diag2.southWest()) & empty;
+    }
+
+    return (result | diag1.northWest() | diag1.southEast() | diag2.northEast() | diag2.southWest()) & ~bishops;
+}
+
+BitBoard BitBoard::pawnNorthAttacks(BitBoard pawns, BitBoard targets) {
+    return (pawns.northEast() | pawns.northWest()) & targets;
+}
+BitBoard BitBoard::pawnNorthMoves(BitBoard pawns, BitBoard empty) {
+    pawns = pawns.north() & empty;
+    return (pawns | (pawns.north() & Rank4)) & empty;
+}
+
+BitBoard BitBoard::pawnSouthAttacks(BitBoard pawns, BitBoard targets) {
+    return (pawns.southEast() | pawns.southWest()) & targets;
+}
+BitBoard BitBoard::pawnSouthMoves(BitBoard pawns, BitBoard empty) {
+    pawns = pawns.south() & empty;
+    return (pawns | (pawns.south() & Rank5)) & empty;
 }