Use some constants

src/main.rs

@@ -9,6 +9,10 @@ mod prelude {
     pub use crate::resources::*;
     pub use crate::systems::*;
     pub use bevy::prelude::*;
+
+    pub const SCREEN_WIDTH: f32 = 80.0;
+    pub const SCREEN_HEIGHT: f32 = 50.0;
+    pub const TILE_SIZE: f32 = 64.0;
 }
 
 use prelude::*;

src/systems/mod.rs

@@ -11,9 +11,9 @@ pub fn setup(
 
     // Map
     let grass_material = materials.add(asset_server.load("grass.png").into());
-    let tile_size = Vec2::new(64.0, 64.0);
+    let tile_size = Vec2::new(TILE_SIZE, TILE_SIZE);
     let sprite = Sprite::new(tile_size);
-    let map_size = Vec2::new(80.0, 50.0);
+    let map_size = Vec2::new(SCREEN_HEIGHT, SCREEN_HEIGHT);
     let half_x = (map_size.x / 2.0) as i32;
     let half_y = (map_size.y / 2.0) as i32;
 
@@ -45,7 +45,7 @@ pub fn add_player(
         .insert(Name("Player 1".to_string()))
         .insert_bundle(SpriteBundle {
             material: player_material,
-            sprite: Sprite::new(Vec2::new(64.0, 64.0)),
+            sprite: Sprite::new(Vec2::new(TILE_SIZE, TILE_SIZE)),
             transform: Transform::from_translation(Vec3::new(0.0, 0.0, 1.0)),
             ..Default::default()
         });