Scene: Add time as the amount of seconds it has been enabled.

src/myou_engine.nim

@@ -188,6 +188,7 @@ proc myou_main_loop*(self: MyouEngine) =
     for _,scene in self.scenes.pairs:
         if not scene.enabled:
             continue
+        scene.time += delta_seconds
         for f in scene.pre_draw_callbacks:
             f(scene, delta_seconds)
     self.renderer.draw_all()

src/types.nim

@@ -373,6 +373,7 @@ type
         active_camera*: Camera
         physics_enabled*: bool
         world*: World
+        time*: float
 
         # render options
         background_color*: Vec4