Timing Module Update

- Implement a new timing module
- Utilize the new timing module in glium platform implementation for frame limiting and fixed engine updates timing.

engine/src/engine.rs

@@ -44,7 +44,7 @@ impl EngineTrait for Engine {
     }
 
     /// Update the engine
-    fn update(&mut self, platform_context: PlatformContext) {
+    fn frame_update(&mut self, platform_context: PlatformContext) {
         self.debug_ui_buffer.borrow_mut().reset_buffer();
         let mut ctx = SystemContext {
             scene: self.scene_manager.current_mut(),
@@ -53,7 +53,19 @@ impl EngineTrait for Engine {
         };
 
         for system in self.system_manager.systems.values_mut() {
-            system.update(&mut ctx);
+            system.frame_update(&mut ctx);
+        }
+    }
+
+    fn fixed_update(&mut self, platform_context: PlatformContext) {
+        let mut ctx = SystemContext {
+            scene: self.scene_manager.current_mut(),
+            platform_context,
+            debug_ui_buffer: self.debug_ui_buffer.clone(),
+        };
+
+        for system in self.system_manager.systems.values_mut() {
+            system.fixed_update(&mut ctx);
         }
     }