code: def unbind(self):
          
          # Unbind the FBO
          if self.texture.mipmap:
              with self.texture:
                  self.texture.generate_mipmap()
  
          gl.glBindFramebufferEXT(gl.GL_FRAMEBUFFER_EXT, 0)
  
          # Restore the old viewport size
          gl.glViewport(*self._old_viewport)
docs: Unbind the FBO.