Factor out components

src/components.rs

+use specs::prelude::*;
+use specs_derive::Component;
+use sdl2::rect::{Point, Rect};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Direction {
+    Up,
+    Down,
+    Left,
+    Right,
+}
+
+#[derive(Component, Debug)]
+#[storage(VecStorage)]
+pub struct Position(Point);
+
+#[derive(Component, Debug)]
+#[storage(VecStorage)]
+pub struct Velocity {
+    pub speed: i32,
+    pub direction: Direction,
+}
+
+#[derive(Component, Debug, Clone)]
+#[storage(VecStorage)]
+pub struct Sprite {
+    pub spritesheet: usize,
+    pub region: Rect,
+}
+
+#[derive(Component, Debug)]
+#[storage(VecStorage)]
+pub struct MovementAnimation {
+    pub current_frame: usize,
+    pub up_frames: Vec<Sprite>,
+    pub down_frames: Vec<Sprite>,
+    pub left_frames: Vec<Sprite>,
+    pub right_frames: Vec<Sprite>,
+}

src/main.rs

+mod components;
+
 use sdl2::pixels::Color;
 use sdl2::event::Event;
 use sdl2::keyboard::Keycode;
 
 use std::time::Duration;
 
-const PLAYER_MOVEMENT_SPEED: i32 = 20;
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-enum Direction {
-    Up,
-    Down,
-    Left,
-    Right,
-}
-
-#[derive(Component, Debug)]
-#[storage(VecStorage)]
-struct Position(Point);
-
-#[derive(Component, Debug)]
-#[storage(VecStorage)]
-struct Velocity {
-    speed: i32,
-    direction: Direction,
-}
-
-#[derive(Component, Debug, Clone)]
-#[storage(VecStorage)]
-struct Sprite {
-    spritesheet: usize,
-    region: Rect,
-}
-
-#[derive(Component, Debug)]
-#[storage(VecStorage)]
-struct MovementAnimation {
-    current_frame: usize,
-    up_frames: Vec<Sprite>,
-    down_frames: Vec<Sprite>,
-    left_frames: Vec<Sprite>,
-    right_frames: Vec<Sprite>,
-}
+use crate::components::*;
 
-#[derive(Debug)]
-struct Player {
-    position: Point,
-    sprite: Rect,
-    speed: i32,
-    direction: Direction,
-    current_frame: i32,
-}
+const PLAYER_MOVEMENT_SPEED: i32 = 20;
 
 fn direction_spritesheet_row(direction: Direction) -> i32 {
     use self::Direction::*;
         down_frames: character_animation_frames(player_spritesheet, player_top_left_frame, Direction::Down),
         left_frames: character_animation_frames(player_spritesheet, player_top_left_frame, Direction::Left),
         right_frames: character_animation_frames(player_spritesheet, player_top_left_frame, Direction::Right),
-    }
+    };
 
     let mut world = World::new();
 
     world.create_entity()
         .with(Position(Point::new(0, 0)))
-        .with(Velocity {speed: 0, direction: Direction::Right}),
+        .with(Velocity {speed: 0, direction: Direction::Right})
         .with(player_animation.right_frames[0].clone())
         .with(player_animation)
         .build();