minor changes and added namespace to avoid conflicts when integrating with PanoPainter

engine/app.h

@@ -8,6 +8,8 @@
 
 class App
 {
+public:
+    static App I;
     Sampler sampler;
     Texture2D tex;
     LayoutManager layout;
@@ -17,9 +19,8 @@ class App
     NodePopupMenu* menu_file = nullptr;
     NodePopupMenu* menu_edit = nullptr;
     NodePopupMenu* menu_layers = nullptr;
+    NodeBorder* sidebar = nullptr;
     const uint16_t main_id = const_hash("main");
-public:
-    static App I;
     float width;
     float height;
 #ifdef __ANDROID__
@@ -32,6 +33,7 @@ public:
     void initAssets();
     void initLayout();
     void create();
+    void clear();
     void update(float dt);
     void resize(float w, float h);
     void mouse_down(int button, float x, float y);