def _check_pyopengl_3D():
 global USE_TEX_3D
 USE_TEX_3D = True
 try:
  import OpenGL.GL as _gl
 except ImportError:
  raise ImportError('PyOpenGL is required for 3D texture support')
 return _gl

def _check_pyopengl_3D ( ) : global USE_TEX_3D USE_TEX_3D = True try : import OpenGL . GL as _gl except ImportError : raise ImportError ( 'PyOpenGL is required for 3D texture support' ) return _gl
helper to ensure users have opengl for 3d texture support .