Implement halfmove/fullmove counters

src/move.rs

@@ -125,8 +125,9 @@ impl Board {
                 Some(mv.src - 8),
             ),
         };
+        let pawn_move = Self::is_pawn_move(mv.src, &own_pieces[Kind::Pawn]);
 
-        Self::update_game_state(&mut self.state, mv.src, mv.dst, color);
+        Self::update_game_state(&mut self.state, mv, color, pawn_move);
 
         match &mv.move_type {
             MoveType::Quiet => {
@@ -161,10 +162,12 @@ impl Board {
         }
     }
 
-    fn update_game_state(state: &mut State, src: usize, dst: usize, color: Color) {
+    fn update_game_state(state: &mut State, mv: &Move, color: Color, pawn_move: bool) {
         state.set_en_passant_target_square(None);
-        state.update_castling_state_quiet(src, color);
-        state.update_castling_state_capture(dst, Color::opponent_color(color));
+        state.update_castling_state_quiet(mv.src, color);
+        state.update_castling_state_capture(mv.dst, Color::opponent_color(color));
+        state.update_half_move(mv.move_type, pawn_move);
+        state.update_full_move(color);
         state.change_side();
     }
 
@@ -214,6 +217,10 @@ impl Board {
 
         Self::remove_piece(piece_to_remove, pieces);
     }
+
+    const fn is_pawn_move(square: usize, pawns: &Piece) -> bool {
+        have_common_bit(square_to_bitboard(square), pawns.bitboard)
+    }
 }
 
 #[cfg(test)]
@@ -257,7 +264,7 @@ mod tests {
 
     const FEN_EN_PASSANT: [&str; 2] = [
         "r3k2r/2p1p1qp/2npb3/1p3p2/p3P1pP/P1PB1Q2/1P1PNPP1/R3K2R b KQkq h3 0 1",
-        "r3k2r/2p1p1qp/2npb3/1p3p2/p3P3/P1PB1Q1p/1P1PNPP1/R3K2R w KQkq - 0 1",
+        "r3k2r/2p1p1qp/2npb3/1p3p2/p3P3/P1PB1Q1p/1P1PNPP1/R3K2R w KQkq - 0 2",
     ];
 
     #[test]
@@ -316,7 +323,7 @@ mod tests {
 
     const FEN_CASTLE: [&str; 2] = [
         "r3k2r/2p1p1qp/2npb3/1p3p2/p3P1pP/P1PB1Q2/1P1PNPP1/R3K2R w KQkq - 0 1",
-        "r3k2r/2p1p1qp/2npb3/1p3p2/p3P1pP/P1PB1Q2/1P1PNPP1/R4RK1 b kq - 0 1",
+        "r3k2r/2p1p1qp/2npb3/1p3p2/p3P1pP/P1PB1Q2/1P1PNPP1/R4RK1 b kq - 1 1",
     ];
 
     #[test]

src/state.rs

@@ -1,4 +1,4 @@
-use crate::board::Color;
+use crate::{board::Color, r#move::MoveType};
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct State {
@@ -80,6 +80,21 @@ impl State {
         }
     }
 
+    pub fn update_half_move(&mut self, move_type: MoveType, pawn_move: bool) {
+        if move_type == MoveType::Capture || pawn_move {
+            self.halfmove_clock = 0;
+        } else {
+            self.halfmove_clock += 1;
+        }
+    }
+
+    pub fn update_full_move(&mut self, color: Color) {
+        match color {
+            Color::White => (),
+            Color::Black => self.fullmove_counter += 1,
+        }
+    }
+
     pub fn change_side(&mut self) {
         self.side_to_move = match self.side_to_move {
             Color::White => Color::Black,