text: #ifndef _OPENGLAPP_H_
  #define _OPENGLAPP_H_
  
  #ifdef _MSC_VER
  #include <Windows.h>
  #include <GL/GL.h>
  #elif __APPLE__
  #include <OpenGL/GL.h>
  #endif
  
  #include <GL/freeglut.h>
  
  class OpenGLApplication {
  public:
  	OpenGLApplication();
  	~OpenGLApplication();
  	void Initialize();
  	// FreeGLUT callbacks //
  	virtual void Keyboard(unsigned char key, int x, int y);
  	virtual void KeyboardUp(unsigned char key, int x, int y);
  	virtual void Special(int key, int x, int y);
  	virtual void SpecialUp(int key, int x, int y);
  	virtual void Reshape(int w, int h);
  	virtual void Idle();
  	virtual void Mouse(int button, int state, int x, int y);
  	virtual void PassiveMotion(int x, int y);
  	virtual void Motion(int x, int y);
  	virtual void Display();
  };
  
  #endif
  