Add Settings with fullscreen and windowed options, a config file

(settings.toml) to persist settings, fix a bug in platform code where
innner window size wasn't updated on resize, various other tweaks

game/src/systems/display_settings.rs

@@ -0,0 +1,92 @@
+use std::sync::{Arc, Mutex};
+use raidillon_app::prelude::*;
+use crate::systems::common::should_draw_menu;
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum SettingsTab {
+    Display,
+}
+
+impl Default for SettingsTab {
+    fn default() -> Self {
+        SettingsTab::Display
+    }
+}
+
+#[derive(Clone, Default)]
+struct DisplaySettingsUiState {
+    selected_fullscreen_mode: WindowMode,
+    active_tab: SettingsTab,
+}
+
+#[derive(Default)]
+pub struct DisplaySettings {
+    ui_state: Arc<Mutex<DisplaySettingsUiState>>,
+}
+
+impl System for DisplaySettings {
+    fn load_world(&mut self, res: &mut EngineResources, scene: &mut Scene) {
+        let pctx = res.get_mut::<PlatformContext>().unwrap();
+
+        // sync the settings with UI state once
+        if let (Ok(settings_handle), Ok(mut state)) = (pctx.settings.read(), self.ui_state.lock()) {
+            state.selected_fullscreen_mode = settings_handle.display_settings.fullscreen_mode;
+        }
+    }
+
+    fn frame_update(&mut self, res: &mut EngineResources, scene: &mut Scene) {
+        if should_draw_menu(scene) {
+            let pctx = res.get_mut::<PlatformContext>().unwrap();
+            let settings = pctx.settings.clone();
+            let ui_state = self.ui_state.clone();
+
+            pctx.egui_queue.borrow_mut().queue(move |egui_ctx| {
+                egui::Window::new("Settings").default_open(false).show(egui_ctx, |ui| {
+                    let mut state = ui_state.lock().unwrap();
+
+                    ui.horizontal(|ui| {
+                        ui.selectable_value(&mut state.active_tab, SettingsTab::Display, "Display Settings");
+                    });
+                    ui.separator();
+
+                    match state.active_tab {
+                        SettingsTab::Display => {
+                            ui.label("Window Mode");
+                            egui::ComboBox::from_id_salt("window_mode")
+                                .selected_text(window_mode_label(state.selected_fullscreen_mode))
+                                .show_ui(ui, |ui| {
+                                    for mode in [
+                                        WindowMode::Windowed,
+                                        WindowMode::BorderlessFullscreen,
+                                    ] {
+                                        ui.selectable_value(
+                                            &mut state.selected_fullscreen_mode,
+                                            mode,
+                                            window_mode_label(mode),
+                                        );
+                                    }
+                                });
+
+                            ui.add_space(8.0);
+                            ui.with_layout(egui::Layout::right_to_left(egui::Align::Center), |ui| {
+                                if ui.button("Apply").clicked() {
+                                    if let Ok(mut settings_handle) = settings.write() {
+                                        settings_handle.display_settings.fullscreen_mode = state.selected_fullscreen_mode;
+                                        settings_handle.display_settings.dirty = true;
+                                    }
+                                }
+                            });
+                        }
+                    }
+                });
+            });
+        }
+    }
+}
+
+fn window_mode_label(mode: WindowMode) -> &'static str {
+    match mode {
+        WindowMode::Windowed => "Windowed",
+        WindowMode::BorderlessFullscreen => "Borderless Fullscreen",
+    }
+}