re-added missing code for check tests from past branch

engine/src/bitboard/board.rs

@@ -64,7 +64,7 @@ impl Board {
 
     for (i, c) in coming_up.chars().enumerate() {
       if pieces.contains(&c) {
-        // board.place_piece(row*8 + col, c);
+        board.place_piece(row*8 + col, c);
         col += 1;
       }
       else if ('1'..='8').contains(&c) {
@@ -179,4 +179,21 @@ impl Board {
     }
   }
 
+  pub fn place_piece(&mut self, sq: i32, piece: char) {
+    match piece {
+      'p' => {self.bitboards[6] |= 1 << sq}
+      'n' => {self.bitboards[7] |= 1 << sq}
+      'b' => {self.bitboards[8] |= 1 << sq}
+      'r' => {self.bitboards[9] |= 1 << sq}
+      'q' => {self.bitboards[10] |= 1 << sq}
+      'k' => {self.bitboards[11] |= 1 << sq}
+      'P' => {self.bitboards[0] |= 1 << sq}
+      'N' => {self.bitboards[1] |= 1 << sq}
+      'B' => {self.bitboards[2] |= 1 << sq}
+      'R' => {self.bitboards[3] |= 1 << sq}
+      'Q' => {self.bitboards[4] |= 1 << sq}
+      'K' => {self.bitboards[5] |= 1 << sq}
+       _  => ()
+    }
+  }
 }

engine/src/bitboard/legality.rs

@@ -1,8 +1,56 @@
 use super::board::Board;
 use super::attackmaps::RAY_TABLE;
+use super::checkinfo::CheckInfo;
+use super::attacks::get_raycast_from_square_in_direction;
 
 impl Board {
 
+  pub fn check_test(&self) -> CheckInfo {
+    let mut check_info: CheckInfo = CheckInfo::new();
+    let offset: usize = 6 * self.side_to_move as usize;
+    let king: u64 = self.bitboards[5 + offset];
+    let king_sq = king.trailing_zeros() as usize;
+    let occupancy = self.occupancy[2];
+
+    // queen-rook checks (+)
+    let attacker_mask = self.bitboards[10 - offset] | self.bitboards[9 - offset];
+
+    for dir in [0, 2, 4, 6] {
+      let threat_mask: u64 = get_raycast_from_square_in_direction(occupancy, king_sq, dir);
+      if threat_mask & attacker_mask != 0 {
+        check_info.add_checker(threat_mask);
+      }
+    }
+
+    // queen-bishop checks (x)
+    let attacker_mask = self.bitboards[10 - offset] | self.bitboards[8 - offset];
+
+    for dir in [1, 3, 5, 7] {
+      let threat_mask = get_raycast_from_square_in_direction(occupancy, king_sq, dir);
+      if threat_mask & attacker_mask != 0 {
+        check_info.add_checker(threat_mask);
+      }
+    }
+
+    // knight checks (L)
+    let attacker_mask = self.bitboards[7 - offset];
+    let threat_mask = self.get_pseudo_knight_moves(king_sq as u32);
+    let checker = threat_mask & attacker_mask;
+    if checker != 0 {
+      check_info.add_checker(checker);
+    }
+
+    // pawn checks (v)
+    let attacker_mask = self.bitboards[6 - offset];
+    let threat_mask = self.get_pseudo_pawn_captures(king_sq as u32);
+    let checker = threat_mask & attacker_mask;
+    if checker != 0 {
+      check_info.add_checker(checker);
+    }
+
+    return check_info;
+  }
+
   pub(in super) fn calc_pinned_squares(&mut self) {
     self.pinned_squares = [4; 64];
     self.pin_mask = 0u64;
@@ -45,4 +93,35 @@ impl Board {
     }
   }
 
+}
+
+// <----- TESTS ----->
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn check_test_test() {
+
+    let fens = [
+      "rnb1k1nr/pppppppp/4q3/8/1b6/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",      // no check
+      "rnb1k1nr/pppppppp/4q3/8/1b1P4/8/PPP1PPPP/RNBQKBNR w KQkq d3 0 1",   // single check
+      "rnb1k1nr/ppp1p2p/3pq1p1/8/1b1P1P2/8/PPP2PPP/RNBQKBNR w KQkq - 0 1"  // double check
+      ];
+    let expected_results = [
+      CheckInfo { check_count: 0, move_mask: 0xFFFF_FFFF_FFFF_FFFF },
+      CheckInfo { check_count: 1, move_mask: 0x0000_0000_0204_0800 },
+      CheckInfo { check_count: 2, move_mask: 0x0000_0000_0000_0000 }
+    ];
+
+    for test_nr in 0..3 {
+      let fen = fens[test_nr];
+      let board =  Board::build(fen);
+      let check_test_actual = board.check_test();
+      assert_eq!(check_test_actual.check_count, expected_results[test_nr].check_count);
+      assert_eq!(check_test_actual.move_mask, expected_results[test_nr].move_mask);
+    }
+
+  }
 }