Clean up example code.

+ Fix spartan path.
+ Fix triangle draw mode.

src/qtk/scene.cpp

@@ -58,6 +58,8 @@ void Scene::draw() {
     mInit = true;
   }
 
+  // Check if there were new models added that still need to be loaded.
+  // This is for objects added at runtime via click-and-drag events, etc.
   while(!mModelLoadQueue.empty()) {
     auto modelSpec = mModelLoadQueue.front();
     // Load the model and add it to the scene.

src/qtk/scene.h

@@ -53,7 +53,7 @@ namespace Qtk {
 
       Scene();
 
-      virtual ~Scene();
+      ~Scene() override;
 
       /*************************************************************************
        * Public Methods
@@ -73,10 +73,13 @@ namespace Qtk {
 
       /**
        * Function called to update the QOpenGLWidget. Does not trigger a redraw.
-       *
+       * This method can translate or rotate objects to simulate movement.
        * Calling this several times will still result in only one repaint.
+       *
+       * It's very possible a client will not want to move objects in the scene
+       * using this method. This is intentially not pure virtual.
        */
-      virtual void update() {}
+      virtual void update() { }
 
       void loadModel(const QUrl & url) {
         auto fileName = url.fileName().replace(".obj", "").toStdString();
@@ -239,30 +242,6 @@ namespace Qtk {
       /* Track count of objects with same initial name. */
       std::unordered_map<std::string, uint64_t> mObjectCount;
   };
-
-  class SceneEmpty : public Scene {
-    public:
-      void init() override { setSceneName("Empty Scene"); }
-
-      void draw() override { Scene::draw(); }
-
-      void update() override { Scene::update(); }
-  };
-
-  class SceneInterface : public Scene {
-    public:
-      explicit SceneInterface(Scene * scene) : mScene(scene) {}
-
-      void init() override { mScene->init(); }
-
-      void draw() override { mScene->draw(); }
-
-      void update() override { mScene->update(); }
-
-    protected:
-      Scene * mScene;
-  };
-
 }  // namespace Qtk
 
 #endif  // QTK_SCENE_H