def main():
pygame.init()
screen=pygame.display.set_mode((500,500),0,24)
bg=pygame.surface.Surface((500,500),0,24)
clock=pygame.time.Clock()
i=Curve("bezier")
i.set_passthru(((50,250),(450,250)))
i.set_control(((100,100),(300,100)))
steps=2
points=i.yieldall(60)
while 1:
clock.tick(60)
steps+=1
if steps==60:
steps=2
bg.fill((255,255,255))
pygame.draw.aalines(bg,(0,0,0),0,list(points[i] for i in range(steps)))
pygame.draw.aalines(bg,(0,0,0),0,(points[0],points[steps]))
pygame.draw.rect(bg,(255,0,0),Rect(50,250,5,5))
pygame.draw.rect(bg,(255,0,0),Rect(450,250,5,5))
pygame.draw.rect(bg,(255,0,0),Rect(100,100,5,5))
pygame.draw.rect(bg,(255,0,0),Rect(300,100,5,5))
screen.blit(bg,(0,0))
pygame.display.update()
