feat: Refactor ImGuiAppExtension's onRender to onUpdate

The onRender method in ImGuiAppExtension has been refactored as an onUpdate method to handle changes over time rather than frame-by-frame. Now, each window in the application iterates through specific ImGuiContextWrapper updates. This change ensures more efficient and reliable context updates for every window in the application.

big2/include/big2/imgui/imgui_app_extension.h

@@ -24,7 +24,7 @@ class ImGuiAppExtension final : public AppExtensionBase {
  protected:
   void OnWindowCreated(Window& window) override;
   void OnWindowDestroyed(Window& window) override;
-  void OnRender(Window& window) override;
+  void OnUpdate(std::float_t dt) override;
 
  private:
   std::vector<ImGuiContextWrapper> contexts_;

big2/src/imgui/imgui_app_extension.cpp

@@ -57,20 +57,22 @@ void ImGuiAppExtension::OnWindowDestroyed(Window& window) {
                 });
 }
 
-void ImGuiAppExtension::OnRender(Window& window) {
-  AppExtensionBase::OnRender(window);
+void ImGuiAppExtension::OnUpdate(std::float_t dt) {
+  AppExtensionBase::OnUpdate(dt);
 
-  std::optional<ImGuiContextWrapper> maybe_context = big2::FirstIf<ImGuiContextWrapper>(contexts_.begin(), contexts_.end(), [&window](ImGuiContextWrapper& context) {
-    return context.GetWindow() == window.GetWindowHandle();
-  });
+  for(Window& window : app_->GetWindows()) {
+    std::optional<ImGuiContextWrapper> maybe_context = big2::FirstIf<ImGuiContextWrapper>(contexts_.begin(), contexts_.end(), [&window](ImGuiContextWrapper& context) {
+      return context.GetWindow() == window.GetWindowHandle();
+    });
 
-  if(!maybe_context.has_value())
-  {
-    return;
-  }
+    if(!maybe_context.has_value())
+    {
+      return;
+    }
 
-  ImGui::SetCurrentContext(maybe_context.value().GetContext());
-  big2::GlfwEventQueue::UpdateImGuiEvents(window.GetWindowHandle());
+    ImGui::SetCurrentContext(maybe_context.value().GetContext());
+    big2::GlfwEventQueue::UpdateImGuiEvents(window.GetWindowHandle());
+  }
 }
 
 }