def on_draw(self, time=None):
        glClearColor(0.0, 0.0, 0.0, 1.0)
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glLoadIdentity()

        self.particles.append(Particle())
        for particle in self.particles:
            particle.draw()

            if particle.is_dead:
                self.particles.remove(particle)