Implement Knight

rs/src/board.rs

@@ -154,9 +154,11 @@ impl GridAxis for File {
 #[derive(Clone)]
 pub enum PieceType {
     Pawn,
+    Knight,
 }
 
 impl PieceType {
+    // Pawn
     fn new_pawn(color: Color, file: File) -> (Piece, Position) {
         let pos = Position::new(file, color.get_pawn_rank());
         (
@@ -207,6 +209,36 @@ impl PieceType {
         }
         capture_rays
     }
+
+    // Knight
+    fn new_knight(color: Color, file: File) -> (Piece, Position) {
+        let pos = Position::new(file, color.get_home_rank());
+        (
+            Piece {
+                piece_type: PieceType::Knight,
+                color,
+            },
+            pos,
+        )
+    }
+    fn knight_rays(position: &Position) -> Vec<Ray> {
+        [
+            &[&Dir::Up, &Dir::Up, &Dir::Left],
+            &[&Dir::Up, &Dir::Up, &Dir::Right],
+            &[&Dir::Right, &Dir::Right, &Dir::Up],
+            &[&Dir::Right, &Dir::Right, &Dir::Down],
+            &[&Dir::Down, &Dir::Down, &Dir::Right],
+            &[&Dir::Down, &Dir::Down, &Dir::Left],
+            &[&Dir::Left, &Dir::Left, &Dir::Down],
+            &[&Dir::Left, &Dir::Left, &Dir::Up],
+        ]
+        .into_iter()
+        .filter_map(|dirs| position.chain(dirs))
+        .map(|p| Ray {
+            positions: vec![p],
+        })
+        .collect()
+    }
     fn initial_setup(&self) -> Vec<(Piece, Position)> {
         match &self {
             PieceType::Pawn => vec![
@@ -227,6 +259,12 @@ impl PieceType {
                 PieceType::new_pawn(Color::Black, File::G),
                 PieceType::new_pawn(Color::Black, File::H),
             ],
+            PieceType::Knight => vec![
+                PieceType::new_knight(Color::White, File::B),
+                PieceType::new_knight(Color::White, File::G),
+                PieceType::new_knight(Color::Black, File::B),
+                PieceType::new_knight(Color::Black, File::G),
+            ],
         }
     }
 }
@@ -246,6 +284,7 @@ impl Piece {
             PieceType::Pawn => {
                 PieceType::pawn_move_rays(position, &self.color)
             }
+            PieceType::Knight => PieceType::knight_rays(position),
         }
     }
     fn get_capture_rays(&self, position: &Position) -> Vec<Ray> {
@@ -253,6 +292,7 @@ impl Piece {
             PieceType::Pawn => {
                 PieceType::pawn_capture_rays(position, &self.color)
             }
+            PieceType::Knight => PieceType::knight_rays(position),
         }
     }
 }
@@ -294,7 +334,7 @@ impl Board {
     }
     pub fn reset(&mut self) {
         self.state.clear();
-        for piece_type in &[PieceType::Pawn] {
+        for piece_type in &[PieceType::Pawn, PieceType::Knight] {
             for (piece, position) in piece_type.initial_setup() {
                 self.set_at(position, Some(piece));
             }

rs/src/ui.rs

@@ -16,6 +16,7 @@ impl std::fmt::Display for board::PieceType {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match self {
             board::PieceType::Pawn => write!(f, "P"),
+            board::PieceType::Knight => write!(f, "N"),
         }
     }
 }