text: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  # -----------------------------------------------------------------------------
  # Copyright (c) 2014, Vispy Development Team.
  # Distributed under the (new) BSD License. See LICENSE.txt for more info.
  # -----------------------------------------------------------------------------
  from vispy.gloo import gl
  
  
  def on_display():
      gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT)
      glut.glutSwapBuffers()
  
  
  def on_keyboard(key, x, y):
      if key == '\033':
          sys.exit()
  
  
  def on_idle():
      global t, t0, frames
      t = glut.glutGet(glut.GLUT_ELAPSED_TIME)
      frames = frames + 1
      elapsed = (t - t0) / 1000.0
      if elapsed > 2.5:
          print("FPS : %.2f (%d frames in %.2f second)"
                % (frames / elapsed, frames, elapsed))
          t0, frames = t, 0
      glut.glutPostRedisplay()
  
  
  if __name__ == '__main__':
      import sys
      import OpenGL.GLUT as glut
  
      glut.glutInit(sys.argv)
      glut.glutInitDisplayMode(
          glut.GLUT_DOUBLE | glut.GLUT_RGB | glut.GLUT_DEPTH)
      glut.glutInitWindowSize(512, 512)
      glut.glutCreateWindow("Do nothing benchmark (GLUT)")
      glut.glutDisplayFunc(on_display)
      glut.glutKeyboardFunc(on_keyboard)
  
      t0, frames, t = glut.glutGet(glut.GLUT_ELAPSED_TIME), 0, 0
      glut.glutIdleFunc(on_idle)
      glut.glutMainLoop()
  