Add get_all_occupancies, is_attacked method and unit tests

src/attack.rs

@@ -370,6 +370,14 @@ pub fn init_rook_attacks() {
     }
 }
 
+pub fn init_attacks() {
+    init_pawn_attacks();
+    init_knight_attacks();
+    init_king_attacks();
+    init_bishop_attacks();
+    init_rook_attacks()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/board.rs

@@ -1,6 +1,11 @@
 use std::fmt;
 use u64 as Bitboard;
 
+use crate::attack::{
+    get_bishop_attacks, get_king_attacks, get_knight_attacks, get_pawn_attacks, get_queen_attacks,
+    get_rook_attacks,
+};
+
 #[derive(Debug, PartialEq, Eq)]
 pub struct Board {
     white_pieces: [Piece; 6],
@@ -12,17 +17,17 @@ impl Board {
         Self {
             white_pieces: [
                 Piece::new(0xff00, Kind::Pawn, Color::White),
-                Piece::new(0x81, Kind::Rook, Color::White),
                 Piece::new(0x42, Kind::Knight, Color::White),
                 Piece::new(0x24, Kind::Bishop, Color::White),
+                Piece::new(0x81, Kind::Rook, Color::White),
                 Piece::new(0x8, Kind::Queen, Color::White),
                 Piece::new(0x10, Kind::King, Color::White),
             ],
             black_pieces: [
                 Piece::new(0xff000000000000, Kind::Pawn, Color::Black),
-                Piece::new(0x8100000000000000, Kind::Rook, Color::Black),
                 Piece::new(0x4200000000000000, Kind::Knight, Color::Black),
                 Piece::new(0x2400000000000000, Kind::Bishop, Color::Black),
+                Piece::new(0x8100000000000000, Kind::Rook, Color::Black),
                 Piece::new(0x800000000000000, Kind::Queen, Color::Black),
                 Piece::new(0x1000000000000000, Kind::King, Color::Black),
             ],
@@ -33,17 +38,17 @@ impl Board {
         Self {
             white_pieces: [
                 Piece::new(0x0, Kind::Pawn, Color::White),
-                Piece::new(0x0, Kind::Rook, Color::White),
                 Piece::new(0x0, Kind::Knight, Color::White),
                 Piece::new(0x0, Kind::Bishop, Color::White),
+                Piece::new(0x0, Kind::Rook, Color::White),
                 Piece::new(0x0, Kind::Queen, Color::White),
                 Piece::new(0x0, Kind::King, Color::White),
             ],
             black_pieces: [
                 Piece::new(0x0, Kind::Pawn, Color::Black),
-                Piece::new(0x0, Kind::Rook, Color::Black),
                 Piece::new(0x0, Kind::Knight, Color::Black),
                 Piece::new(0x0, Kind::Bishop, Color::Black),
+                Piece::new(0x0, Kind::Rook, Color::Black),
                 Piece::new(0x0, Kind::Queen, Color::Black),
                 Piece::new(0x0, Kind::King, Color::Black),
             ],
@@ -52,10 +57,32 @@ impl Board {
 
     pub fn set_piece(&mut self, piece: Piece) {
         match piece.color {
-            Color::Black => self.black_pieces[piece.kind as usize].bitboard |= piece.bitboard,
-            Color::White => self.white_pieces[piece.kind as usize].bitboard |= piece.bitboard,
+            Color::Black => self.black_pieces[piece.kind.idx()].bitboard |= piece.bitboard,
+            Color::White => self.white_pieces[piece.kind.idx()].bitboard |= piece.bitboard,
         };
     }
+
+    pub fn get_all_occupancies(&self) -> Bitboard {
+        let white_blockers = self.white_pieces.iter().fold(0, |acc, p| p.bitboard | acc);
+        let black_blockers = self.black_pieces.iter().fold(0, |acc, p| p.bitboard | acc);
+
+        white_blockers | black_blockers
+    }
+
+    pub fn is_attacked(&self, sq: usize, opponent_color: Color) -> bool {
+        let all_occupancies = self.get_all_occupancies();
+        let enemy = match opponent_color {
+            Color::Black => &self.black_pieces,
+            Color::White => &self.white_pieces,
+        };
+
+        enemy[Kind::Pawn.idx()].bitboard & get_pawn_attacks(sq, opponent_color) != 0
+            || enemy[Kind::Knight.idx()].bitboard & get_knight_attacks(sq) != 0
+            || enemy[Kind::Bishop.idx()].bitboard & get_bishop_attacks(all_occupancies, sq) != 0
+            || enemy[Kind::Rook.idx()].bitboard & get_rook_attacks(all_occupancies, sq) != 0
+            || enemy[Kind::Queen.idx()].bitboard & get_queen_attacks(all_occupancies, sq) != 0
+            || enemy[Kind::King.idx()].bitboard & get_king_attacks(sq) != 0
+    }
 }
 
 impl Default for Board {
@@ -116,18 +143,52 @@ impl fmt::Display for Piece {
     }
 }
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone)]
 pub enum Kind {
     Pawn,
-    Rook,
     Knight,
     Bishop,
+    Rook,
     Queen,
     King,
 }
 
+impl Kind {
+    fn idx(&self) -> usize {
+        *self as usize
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub enum Color {
     White,
     Black,
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::{attack::init_attacks, fen::from_fen};
+
+    use super::*;
+
+    const FEN_EXAMPLE: [&str; 1] = [
+        "8/6P1/4n2b/1p6/1Kp5/6n1/4b3/1k6 w - - 0 1",
+    ];
+
+    #[test]
+    fn test_get_all_occupancies() -> Result<(), String> {
+        let new_game = from_fen(FEN_EXAMPLE[0])?;
+        assert_eq!(new_game.board.get_all_occupancies(), 0x40900206401002);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_is_attacked() -> Result<(), String> {
+        let new_game = from_fen(FEN_EXAMPLE[0])?;
+        init_attacks();
+        assert!(new_game.board.is_attacked(54, Color::Black));
+
+        Ok(())
+    }
+}