Feature: Add skeleton for the tank.

src/main.rs

@@ -5,23 +5,13 @@ use rand::Rng;
 
 use crate::Direction::Left;
 use crate::movable::Movable;
-use crate::ufo::Ufo;
+use crate::movable::tank::Tank;
+use crate::movable::ufo::Ufo;
 
-mod movable;
 mod terminal;
-mod ufo;
-mod tank;
+mod movable;
 
-const WIDTH: u16 = 160;
-const HEIGHT: u16 = 40;
-const HEADER_ROW: u16 = 0;
-const FOOTER_ROW: u16 = HEIGHT - 1;
-const TANK_ROW: u16 = FOOTER_ROW - 1;
-const MIN_UFO_ROW: u16 = 1;
-const MAX_UFO_ROW: u16 = TANK_ROW - 5;
 const DELAY: Duration = Duration::from_millis(10);
-const UFO_STR: &str = "<=000=>";
-const TANK_STR: &str = "⊆≡≣🠭≣≡⊇";
 
 const VERSION: &str = env!("CARGO_PKG_VERSION");
 
@@ -29,6 +19,7 @@ fn main() {
     let terminal = terminal::setup();
 
     const MAX_UFOS: u8 = 100;
+    let mut tank = Tank::create();
     let mut ufos = vec![Ufo::create(), Ufo::create(), Ufo::create(), Ufo::create(), Ufo::create()];
     let mut n_ufos = ufos.len() as u8;
     loop {

src/movable/mod.rs

@@ -1,5 +1,8 @@
 use crate::Direction;
 
+pub mod ufo;
+pub mod tank;
+
 pub trait Movable<T> {
     fn create() -> T;
     fn mov(&mut self, direction: Direction);

src/movable/tank.rs

@@ -0,0 +1,54 @@
+use Direction::{Left, Right};
+
+use crate::Direction;
+use crate::movable::Movable;
+use crate::terminal::{clear_pos, print_str_at, TANK_ROW, WIDTH};
+
+const TANK_STR: &str = "⊆≡≣🠭≣≡⊇";
+
+pub struct Tank {
+    column: u16,
+}
+
+impl Movable<Tank> for Tank {
+    fn create() -> Tank {
+        let column = (WIDTH - (TANK_STR.len() as u16)) / 2;
+        let tank = Tank { column };
+        tank.draw();
+        tank
+    }
+
+    fn mov(&mut self, direction: Direction) {
+        clear(self, &direction);
+        match direction {
+            Left => { todo!("Implement moving left") }
+            Right => { todo!("Implement moving right") }
+            _ => {}
+        }
+    }
+
+    fn draw(&self) {
+        print_str_at(self.column, TANK_ROW, TANK_STR);
+    }
+
+    fn is_on_screen(&self) -> bool {
+        todo!("Implement tank visibility check")
+    }
+}
+
+fn clear(tank: &Tank, direction: &Direction) {
+    match direction {
+        Left => {
+            let right_col = tank.column + (TANK_STR.len() as u16) - 1;
+            if right_col >= TANK_STR.len() as u16 && right_col < WIDTH {
+                clear_pos(right_col, TANK_ROW);
+            }
+        }
+        Right => {
+            if tank.column < WIDTH - (TANK_STR.len() as u16) {
+                clear_pos(tank.column, TANK_ROW);
+            }
+        }
+        _ => {}
+    }
+}

src/movable/ufo.rs

@@ -2,10 +2,12 @@ use std::cmp::{max, min};
 
 use rand::Rng;
 
-use crate::{Direction, MAX_UFO_ROW, MIN_UFO_ROW, UFO_STR, WIDTH};
-use crate::Direction::{Down, Left, Right};
+use crate::Direction;
+use crate::Direction::{Left, Right};
 use crate::movable::Movable;
-use crate::terminal::{clear_pos, print_str_at};
+use crate::terminal::{clear_pos, MAX_UFO_ROW, MIN_UFO_ROW, print_str_at, WIDTH};
+
+const UFO_STR: &str = "<=000=>";
 
 pub struct Ufo {
     row: u16,
@@ -31,27 +33,22 @@ impl Movable<Ufo> for Ufo {
         ufo
     }
 
-    fn mov(&mut self, direction: Direction) {
+    fn mov(&mut self, _direction: Direction) {
         clear(self);
 
-        match direction {
-            Down => { todo!("Implement crash movement (down + direction)") }
-            _ => {
-                match self.direction {
-                    Left => {
-                        let ufo_str_len = UFO_STR.len() as i16;
-                        if self.column >= -ufo_str_len {
-                            self.column -= 1;
-                        }
-                    }
-                    Right => {
-                        if self.column <= WIDTH as i16 {
-                            self.column += 1;
-                        }
-                    }
-                    _ => { /* Ignore, this can't be the case. */ }
-                };
+        match self.direction {
+            Left => {
+                let ufo_str_len = UFO_STR.len() as i16;
+                if self.column >= -ufo_str_len {
+                    self.column -= 1;
+                }
             }
+            Right => {
+                if self.column <= WIDTH as i16 {
+                    self.column += 1;
+                }
+            }
+            _ => { /* Ignore, this can't be the case. */ }
         };
 
         self.draw();

src/tank.rs

@@ -1,25 +0,0 @@
-use crate::movable::Movable;
-use crate::{Direction, TANK_STR, WIDTH};
-
-pub struct Tank {
-    column: u16,
-}
-
-impl Movable<Tank> for Tank {
-    fn create() -> Tank {
-        let column = (WIDTH - TANK_STR.len() as u16) / 2;
-        Tank { column }
-    }
-
-    fn mov(&mut self, direction: Direction) {
-        todo!("Implement tank movement")
-    }
-
-    fn draw(&self) {
-        todo!("Implement drawing tank")
-    }
-
-    fn is_on_screen(&self) -> bool {
-        todo!("Implement tank visibility check")
-    }
-}

src/terminal.rs

@@ -5,7 +5,15 @@ use crossterm::cursor::{Hide, MoveTo, RestorePosition, SavePosition, Show};
 use crossterm::style::Print;
 use crossterm::terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen, SetSize, size};
 
-use crate::{FOOTER_ROW, HEADER_ROW, HEIGHT, VERSION, WIDTH};
+use crate::VERSION;
+
+pub const WIDTH: u16 = 160;
+pub const HEIGHT: u16 = 40;
+const HEADER_ROW: u16 = 0;
+const FOOTER_ROW: u16 = HEIGHT - 1;
+pub const TANK_ROW: u16 = FOOTER_ROW - 1;
+pub const MIN_UFO_ROW: u16 = 1;
+pub const MAX_UFO_ROW: u16 = TANK_ROW - 5;
 
 pub struct Terminal {
     cols: u16,