def on_touch_move(self, touch):
        if self.collide_point(touch.pos[0], touch.pos[1]):
            c = self.current_point
            if c:
                self.points[(c - 1) * 2] = touch.pos[0] - self.pos[0]
                self.points[(c - 1) * 2 + 1] = self.pos[1] - touch.pos[1]
                self.bezier.points = self.points
                self.line.points = self.points + self.points[:2]
                return True
            return super(BezierTest, self).on_touch_move(touch)
dataset/ETHPy150Open kivy/kivy/examples/canvas/bezier.py/BezierTest.on_touch_move/swapped operands of `-`