fix missing `as_any` methods in the glutin backend

src/framework/backend_glutin.rs

@@ -1,17 +1,16 @@
+use std::any::Any;
 use std::cell::{RefCell, UnsafeCell};
 use std::ffi::c_void;
 use std::mem;
 use std::rc::Rc;
 use std::sync::Arc;
 
-use glutin::{Api, ContextBuilder, GlProfile, GlRequest, PossiblyCurrent, WindowedContext};
 use glutin::event::{ElementState, Event, TouchPhase, VirtualKeyCode, WindowEvent};
 use glutin::event_loop::{ControlFlow, EventLoop};
 use glutin::window::WindowBuilder;
+use glutin::{Api, ContextBuilder, GlProfile, GlRequest, PossiblyCurrent, WindowedContext};
 use imgui::{DrawCmdParams, DrawData, DrawIdx, DrawVert};
 
-use crate::game::Game;
-use crate::game::GAME_SUSPENDED;
 use crate::common::Rect;
 use crate::framework::backend::{Backend, BackendEventLoop, BackendRenderer, BackendTexture, SpriteBatchCommand};
 use crate::framework::context::Context;
@@ -19,6 +18,8 @@ use crate::framework::error::GameResult;
 use crate::framework::gl;
 use crate::framework::keyboard::ScanCode;
 use crate::framework::render_opengl::{GLContext, OpenGLRenderer};
+use crate::game::Game;
+use crate::game::GAME_SUSPENDED;
 use crate::input::touch_controls::TouchPoint;
 
 pub struct GlutinBackend;
@@ -44,6 +45,10 @@ impl Backend for GlutinBackend {
 
         Ok(Box::new(GlutinEventLoop { refs: Rc::new(UnsafeCell::new(None)) }))
     }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
 }
 
 pub struct GlutinEventLoop {
@@ -367,6 +372,10 @@ impl BackendEventLoop for GlutinEventLoop {
 
         Ok(Box::new(OpenGLRenderer::new(gl_context, UnsafeCell::new(imgui))))
     }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
 }
 
 fn conv_keycode(code: VirtualKeyCode) -> Option<ScanCode> {