move constants to main and add resize fn

src/engine/objs.rs

@@ -2,7 +2,7 @@ use std::rc::Rc;
 
 use self::obj_traits::MovingObject;
 
-use super::{render::RenderCtx, BG, FG};
+use super::render::RenderCtx;
 
 pub mod geometry;
 pub mod obj_traits;

src/engine/objs/obj_traits.rs

@@ -1,4 +1,7 @@
-use crate::engine::{render::RenderCtx, BG, FG};
+use crate::{
+    engine::{render::RenderCtx, BG},
+    FG,
+};
 
 use super::geometry::{Position, Size};