fix demo/gpudemo build

demo/donttouch/OpenGL3CoreRenderer.h

@@ -0,0 +1,26 @@
+#ifndef OPENGL3_CORE_RENDERER_H
+#define OPENGL3_CORE_RENDERER_H
+
+class btCollisionObject;
+class GLInstancingRenderer;
+
+class OpenGL3CoreRenderer
+{
+
+	GLInstancingRenderer* m_instancingRenderer;
+public:
+	OpenGL3CoreRenderer();
+	virtual ~OpenGL3CoreRenderer();
+	void init();
+	void reshape(int w, int h); 
+	void keyboardCallback(unsigned char key);
+	void renderPhysicsWorld(int numObjects, btCollisionObject** colObjArray, bool syncOnly);
+
+	GLInstancingRenderer*	getInstancingRenderer()
+	{
+		return m_instancingRenderer;
+	}
+};
+
+#endif //OPENGL3_CORE_RENDERER_H
+