text: #pragma once
  
  #ifndef __OPENGL_H__
  #define __OPENGL_H__
  
  #define WIN32_MEAN_AND_LEAN
  #include <Windows.h>
  #include "glew/include/GL/glew.h" // extension lib
  #include "SDL/include/SDL_opengl.h"
  #include <gl/GL.h>
  #include <gl/GLU.h>
  
  #endif