[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;
 }

BitBoard.hpp

@@ -14,6 +14,14 @@ enum DefinedBoards : uint64_t {
     FFile = AFile << 5,
     GFile = AFile << 6,
     HFile = AFile << 7,
+    Rank1 = 0x00000000000000FF,
+    Rank2 = Rank1 << 8,
+    Rank3 = Rank1 << 16,
+    Rank4 = Rank1 << 24,
+    Rank5 = Rank1 << 32,
+    Rank6 = Rank1 << 40,
+    Rank7 = Rank1 << 48,
+    Rank8 = Rank1 << 56,
     WhiteCastlingRank = (1ULL << A2) - 1,
     BlackCastlingRank = (~1ULL << H7),
     CastlingRanks = WhiteCastlingRank | BlackCastlingRank,
@@ -98,15 +106,21 @@ public:
     BitBoard southFill() const;
     BitBoard fileFill() const;
 
+    static BitBoard bishopAttacks(BitBoard pos, BitBoard empty);
     static BitBoard kingAttacks(BitBoard bb);
 
+    static BitBoard pawnNorthAttacks(BitBoard pawns, BitBoard targets);
+    static BitBoard pawnSouthAttacks(BitBoard pawns, BitBoard targets);
+
+    static BitBoard pawnNorthMoves(BitBoard pawns, BitBoard empty);
+    static BitBoard pawnSouthMoves(BitBoard pawns, BitBoard empty);
+
     static BitBoard fromIndex(unsigned i);
 
-    static BitBoard getRank(int r);
-
     // Returns the number of trailing 0-bits in b.
     // WARN: Check for 0!
-    int lsb() const;
+    unsigned lsb() const;
+    unsigned pop();
 
 private:
     U64 mBoard = {};
@@ -255,8 +269,15 @@ inline BitBoard BitBoard::southEast() const {
 inline BitBoard BitBoard::southWest() const {
     return (mBoard >> 9) & ~HFile;
 }
-inline int BitBoard::lsb() const {
+
+inline unsigned BitBoard::lsb() const {
     return __builtin_ctzll(mBoard);
 }
+inline unsigned BitBoard::pop() {
+    unsigned i = lsb();
+    mBoard &= mBoard - 1;
+
+    return i;
+}
 
 #endif //CHESS_ENGINE_BITBOARD_HPP