import sys
from math import *
from pyglet.gl import *
import random

window = pyglet.window.Window()

stuff = []

@window.event
def on_draw():
    global c
    glClear(GL_COLOR_BUFFER_BIT)
    for d in stuff:
        d.draw(GL_LINE_STRIP)

@window.event
def on_mouse_drag(x,y,dx,dy,button,m):
    global stuff
    drawing = stuff[-1]
    drawing.resize(drawing.get_size()+1)
    drawing.vertices[-2] = x
    drawing.vertices[-1] = y

@window.event
def on_mouse_press(x,y,but,mod):
    global stuff
    drawing = pyglet.graphics.vertex_list(1, ('v2f', [x,y]))
    stuff.append(drawing)

pyglet.app.run()