def save_screenshot(self, path, *args, **kwargs):
import PIL.Image
w, h = self.window.size
GL.glReadBuffer(GL.GL_FRONT)
data = GL.glReadPixels(0, 0, w, h, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE)
image = PIL.Image.frombytes(mode="RGBA", size=(w, h), data=data)
image = image.transpose(PIL.Image.FLIP_TOP_BOTTOM)
image.save(path, 'PNG')
