Replace contexts with resources

- Implements a new macro to generate code for a new structure: TypeMap
- TypeMaps are wrappers for HashMaps that use TypeIDs as keys.
- Refactor the entire codebase to use the new resource structures.
- This commit is the first step towards getting rid of "god context objects everywhere".

glium_platform/src/platform.rs

@@ -98,9 +98,12 @@ impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatfor
                     WindowEvent::RedrawRequested => {
                         let mut target = self.display.draw();
                         target.clear_color_and_depth((0.1, 0.1, 0.15, 1.0), 1.0);
-                        let (scene_mut, debug_ui_buffer) = self.engine.scene_and_debug_ui_buffer_mut();
+                        let (scene, debug_ui_buffer) = (
+                            self.engine.current_scene(),
+                            self.engine.get_debug_ui_buffer(),
+                        );
                         let mut context = RenderingContext {
-                            scene: scene_mut,
+                            scene,
                             target: &mut target,
                             asset_manager: self.asset_manager.clone(),
                             window: self.window.clone(),

glium_platform/src/render/debug_ui.rs

@@ -41,7 +41,7 @@ impl RenderingSystem for ImguiBridge {
         self.rendered_this_frame = true;
 
         let ui = self.imgui.frame();
-        ctx.debug_ui_buffer.borrow().write_buffer(&ui);
+        ctx.debug_ui_buffer.write_buffer(&ui);
 
         {
             let window = ctx.window.lock().unwrap();

glium_platform/src/system.rs

@@ -6,7 +6,7 @@ use indexmap::IndexMap;
 use glium::{Display, Frame};
 use glium::glutin::surface::WindowSurface;
 use raidillon_assets::ModelManagerRef;
-use raidillon_core::DebugUIBuffer;
+use raidillon_core::{define_typemap, DebugUIBuffer};
 use raidillon_core::scene::Scene;
 use glam::Vec3;
 
@@ -15,7 +15,7 @@ pub struct RenderingContext<'a> {
     pub target: &'a mut Frame,
     pub window: Arc<Mutex<glium::winit::window::Window>>,
     pub asset_manager: ModelManagerRef,
-    pub debug_ui_buffer: Rc<RefCell<DebugUIBuffer>>,
+    pub debug_ui_buffer: &'a DebugUIBuffer,
     pub env_light_dir: Vec3,
 }
 
@@ -35,6 +35,8 @@ pub trait RenderingSystem {
         Self: Sized;
 }
 
+// define_typemap!(RenderingSystemManager, RenderingSystem);
+
 pub struct RenderingSystemManager {
     pub systems: IndexMap<TypeId, Box<dyn RenderingSystem>>,
 }