adding and integrating ImGuizmo

editor/panels/game_panel.cpp

@@ -0,0 +1,20 @@
+#include "game_panel.hpp"
+
+#include <imgui.h>
+
+void GamePanel::onUpdate(const sophia::FrameInfo&) {
+  syncSceneView(context, sceneViews, view, isShown());
+
+  if (!context.hasScene()) {
+    ImGui::TextDisabled("No scene open");
+    return;
+  }
+
+  const ImVec2 origin = ImGui::GetCursorScreenPos();
+  ui.image(target);
+
+  if (!context.getScene().getActiveCamera()) {
+    ImGui::SetCursorScreenPos(ImVec2(origin.x + 8.0f, origin.y + 8.0f));
+    ImGui::TextDisabled("The scene has no active camera");
+  }
+}