from pyglet.gl import *

window = pyglet.window.Window()

vlist = pyglet.graphics.vertex_list(5, ('v2f', [0,10, 100,1, 200,200, 400,200, 400,300]), ('c3f', [1,0,0, 0,1,0, 0,0,1, 1,1,1, 1,0,1]))

@window.event
def on_draw():
    glClear(pyglet.gl.GL_COLOR_BUFFER_BIT)
    vlist.draw(GL_TRIANGLE_STRIP)


dx = -1
def update(dt):
    global dx
    vlist.vertices[4] += dx
    if vlist.vertices[4] < 0:
        dx = 1
    elif vlist.vertices[4] > 300:
        dx = -1
    
pyglet.clock.schedule_interval(update,1/60.0)
pyglet.app.run()