Fix awkward mouse conflict issues between egui and the engine

game/src/main.rs

@@ -106,6 +106,11 @@ impl System for MainSystem {
             character_pos = tr.translation;
         }
         egui_queue.queue(move |egui_ctx| {
+            // disable text selection on all labels.
+            egui_ctx.style_mut(|style| {
+                style.interaction.selectable_labels = false;
+            });
+
             egui::Window::new("Debug").show(egui_ctx, |ui| {
                 ui.label("Hello World!");
                 ui.label(format!("Frame Delta: {:.3}", time_ctx.frame_dt));

game/src/systems/menu.rs

@@ -42,6 +42,7 @@ impl System for MenuSystem {
         });
     }
 
+
     fn handle_event(&mut self, res: &mut EngineResources, scene: &mut Scene) {
         // The menu is toggled by pressing the escape key
         let input = res.get::<InputState>().unwrap();
@@ -63,18 +64,21 @@ impl MenuSystem {
             .next()
             .unwrap();
 
-        let window = res.get::<PlatformContext>().unwrap().window.lock().unwrap();
+        let pctx = res.get::<PlatformContext>().unwrap();
+        let window = pctx.window.lock().unwrap();
 
         match *menu_state {
             MenuState::Open => {
                 *menu_state = MenuState::Closed;
                 window.set_cursor_grab(CursorGrabMode::Confined).or_else(|_| window.set_cursor_grab(CursorGrabMode::Locked));
                 window.set_cursor_visible(false);
+                pctx.should_egui_receive_input_events.set(false);
             },
             MenuState::Closed => {
                 *menu_state = MenuState::Open;
                 window.set_cursor_grab(CursorGrabMode::None);
                 window.set_cursor_visible(true);
+                pctx.should_egui_receive_input_events.set(true);
             },
         }
     }

glium_platform/src/platform.rs

@@ -1,4 +1,4 @@
-use std::cell::RefCell;
+use std::cell::{RefCell, Cell};
 use std::rc::Rc;
 use std::sync::{Arc, Mutex, RwLock};
 use raidillon_platform::{Platform, PlatformContext, TimeContext};
@@ -31,6 +31,8 @@ pub struct GliumPlatform<E: EngineTrait<PlatformCtx = PlatformContext>> {
     time: time::Time,
     egui_queue: Rc<RefCell<EguiQueue>>,
     settings: Arc<RwLock<Settings>>,
+    /// Used for [`raidillon_platform::context::PlatformContext::should_egui_receive_input_events`]
+    should_egui_receive_input_events: Rc<Cell<bool>>,
 }
 
 impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatform<E> {
@@ -64,6 +66,7 @@ impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatfor
                 Settings::load_or_default(default_config_path()).unwrap()
             )
         );
+        let should_egui_receive_input_events = Rc::new(Cell::new(false));
 
         Self {
             event_loop,
@@ -75,6 +78,7 @@ impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatfor
             time,
             egui_queue,
             settings,
+            should_egui_receive_input_events,
         }
     }
 
@@ -92,6 +96,7 @@ impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatfor
             window: self.window.clone(),
             egui_queue: self.egui_queue.clone(),
             settings: self.settings.clone(),
+            should_egui_receive_input_events: self.should_egui_receive_input_events.clone(),
         };
         self.engine.initialize(ctx.clone());
         self.settings.read().unwrap().display_settings.apply(&*self.window.lock().unwrap());
@@ -136,6 +141,7 @@ impl<E: EngineTrait<PlatformCtx = PlatformContext>> Platform<E> for GliumPlatfor
                             window: self.window.clone(),
                             egui_queue: self.egui_queue.clone(),
                             env_light_dir: Vec3::new(0.0, -1.0, 0.0),
+                            should_egui_receive_input_events: self.should_egui_receive_input_events.clone(),
                         };
 
                         self.rendering_system_manager

glium_platform/src/render/egui.rs

@@ -8,9 +8,12 @@ use crate::system::RenderingContext;
 use egui_glium::EguiGlium;
 use winit::event::{Event, WindowEvent};
 use winit::event_loop::EventLoop;
+use std::cell::Cell;
+use std::rc::Rc;
 
 pub struct EguiRenderer {
     egui_glium: EguiGlium,
+    should_egui_receive_input_events: Option<Rc<Cell<bool>>>,
 }
 
 impl RenderingSystem for EguiRenderer {
@@ -21,10 +24,14 @@ impl RenderingSystem for EguiRenderer {
         let window = window.lock().unwrap();
         let egui_glium = EguiGlium::new(ViewportId::ROOT, &display, &window, &event_loop);
 
-        Self { egui_glium }
+        Self { egui_glium: egui_glium, should_egui_receive_input_events: None }
     }
 
     fn render(&mut self, ctx: &mut RenderingContext) {
+        if self.should_egui_receive_input_events.is_none() {
+            self.should_egui_receive_input_events = Some(ctx.should_egui_receive_input_events.clone());
+        }
+
         let window = ctx.window.lock().unwrap();
 
         self.egui_glium.run(&window, |egui_ctx| {
@@ -38,8 +45,29 @@ impl RenderingSystem for EguiRenderer {
         let window = window.lock().unwrap();
         match event {
             Event::WindowEvent { event, .. } => {
+                let should_egui_receive_input_events = match self.should_egui_receive_input_events.as_ref() {
+                    Some(v) => v.get(),
+                    None => true,
+                };
+
+                let should_send_event = if should_egui_receive_input_events {
+                    true
+                } else {
+                    !matches!(event,
+                        WindowEvent::KeyboardInput { .. } |
+                        WindowEvent::ModifiersChanged(_) |
+                        WindowEvent::CursorMoved { .. } |
+                        WindowEvent::MouseInput { .. } |
+                        WindowEvent::MouseWheel { .. } |
+                        WindowEvent::Touch(_) |
+                        WindowEvent::Ime(_)
+                    )
+                };
+
+                if should_send_event {
                     let _ = self.egui_glium.on_event(&window, &event);
                 }
+            }
             _ => {},
         }
     }

glium_platform/src/system.rs

@@ -10,6 +10,7 @@ use raidillon_core::{define_typemap, EguiQueue};
 use raidillon_core::scene::Scene;
 use glam::Vec3;
 use winit::event_loop::EventLoop;
+use std::cell::Cell;
 
 pub struct RenderingContext<'a> {
     pub scene: &'a Scene,
@@ -19,6 +20,7 @@ pub struct RenderingContext<'a> {
     pub asset_manager: ModelManagerRef,
     pub egui_queue: Rc<RefCell<EguiQueue>>,
     pub env_light_dir: Vec3,
+    pub should_egui_receive_input_events: Rc<Cell<bool>>
 }
 
 /// The internal "rendering system" trait of glium_platform.

platform/src/context.rs

@@ -1,3 +1,4 @@
+use std::cell::Cell;
 use std::{cell::RefCell, rc::Rc};
 use std::sync::{Arc, Mutex, RwLock};
 use winit::event::Event;
@@ -15,6 +16,9 @@ pub struct PlatformContext {
     pub window: Arc<Mutex<winit::window::Window>>,
     pub egui_queue: Rc<RefCell<EguiQueue>>,
     pub settings: Arc<RwLock<Settings>>,
+    /// Sets whether or not egui will receive input events.
+    /// Added to prevent the mouse state conflict between the engine and egui.
+    pub should_egui_receive_input_events: Rc<Cell<bool>>,
 }
 
 #[derive(Clone)]