def METHOD_NAME(self, event):
    self.theta += .5
    self.phi += .5
    model = np.dot(rotate(self.theta, (0, 0, 1)),
                   rotate(self.phi, (0, 1, 0)))
    normal = np.linalg.inv(np.dot(self.view, model)).T
    self.program['u_model'] = model
    self.program['u_normal'] = normal
    self.update()