implemented move generation method for pawn quiet moves

engine/src/bitboard/legality.rs

@@ -93,6 +93,13 @@ impl Board {
     }
   }
 
+  #[inline]
+  pub(in super) fn get_pin_masked_moves(&self, moves: u64, sq: u32) -> u64 {
+    let sq: usize = sq as usize;
+    if self.pinned_squares[sq] == 4 { return moves; }
+    let dir: u8 = self.pinned_squares[sq];
+    return moves & (RAY_TABLE[sq][dir as usize] | RAY_TABLE[sq][4 + dir as usize]);
+  }
 }
 
 // <----- TESTS ----->

engine/src/bitboard/movegen.rs

@@ -2,6 +2,7 @@ mod pawns;
 
 use super::board::Board;
 use super::movebuffer::MoveBuffer;
+use super::bitmove::BitMove;
 
 impl Board {
 

engine/src/bitboard/movegen/pawns.rs

@@ -0,0 +1,38 @@
+use super::*;
+
+impl Board {
+
+  fn add_pawn_quiets(&self, buffer: &mut MoveBuffer, move_mask: u64) {
+    let offset: u8 = self.side_to_move * 6;
+    let mut pawns: u64 = self.bitboards[offset as usize];
+    while pawns != 0 {
+      let next_sq = pawns.trailing_zeros();
+      pawns &= !(1 << next_sq);
+
+      let mut quiets: u64 = self.get_pseudo_pawn_moves(next_sq) & move_mask;
+      quiets = self.get_pin_masked_moves(quiets, next_sq);
+      while quiets != 0 {
+        let to_sq = quiets.trailing_zeros();
+
+        if (self.side_to_move == 0 && quiets.trailing_zeros() / 8 == 7)
+        || (self.side_to_move == 1 && quiets.trailing_zeros() / 8 == 0) {
+          for piece_type in [3, 2, 1, 0] {
+            buffer.add(BitMove::quiet(
+              next_sq as u8,
+              to_sq as u8,
+              Some(piece_type)
+            ));
+          }
+        }
+        else {
+          buffer.add(BitMove::quiet(
+            next_sq as u8,
+            to_sq as u8,
+            None
+          ));
+        }
+        quiets &= !(1 << to_sq);
+      }
+    }
+  }
+}