wiggly.py

from kivy.app import App
from kivy.lang import Builder
from kivy.clock import Clock
from kivy import properties as P


KV = '''
#:import chain itertools.chain
#:import sin math.sin
#:import pi math.pi
#:import rgba kivy.utils.rgba
#:set offset 66

<WigglyLine@Widget>:
    top_func: lambda x: x
    bottom_func: lambda x: x
    step: 6
    color: 0, 0, 0, 0
    points:
        tuple(chain((
        self.x + x,             self.y + self.top_func(x),
        self.x + x,             self.y + self.bottom_func(x + self.step),
        self.x + x + self.step, self.y + self.bottom_func(x + self.step),
        self.x + x + self.step, self.y + self.top_func(x + self.step * 2),
        ) for x in range(-self.width, self.width * 2, self.step * 2)
        )) if self.top_func and self.bottom_func else ()
    canvas:
        Color:
            rgba: self.color
        Line:
            width: 2
            points: self.points or ()
FloatLayout:
    WigglyLine:
        top_func: lambda x: sin(2 * app.time + x) * 20 + 100
        bottom_func: lambda x: sin(2 * app.time + x + pi) * 20 + 50
        color: rgba("FFFFFF")
    WigglyLine:
        top_func: lambda x: sin(2 * app.time + x) * 20 + 150
        bottom_func: lambda x: sin(2 * app.time + x + pi) * 20 + 106
        color: rgba("AAAAAA")
        x: offset
    WigglyLine:
        top_func: lambda x: sin(2 * app.time + x) * 20 + 200
        bottom_func: lambda x: sin(2 * app.time + x + pi) * 20 + 156
        color: rgba("555555")
        x: offset * 2
    WigglyLine:
        top_func: lambda x: sin(2 * app.time + x) * 20 + 250
        bottom_func: lambda x: sin(2 * app.time + x + pi) * 20 + 20e
        color: rgba("333333")
        x: offset * 3
'''


class Application(App):
    time = P.NumericProperty()

    def build(self):
        Clock.schedule_interval(self._update_time, 0)
        return Builder.load_string(KV)

    def _update_time(self, dt):
        self.time -= dt


if __name__ == "__main__":
    Application().run()