Python Pygame绘制直线实现光线反射效果

import time
import numpy as np
import pygame

pygame.init()
screen = pygame.display.set_mode((640, 320))

while True:
    if pygame.QUIT in [e.type for e in pygame.event.get()]:
        pygame.quit()
        break
    time.sleep(0.1)
    pts = (np.random.rand(10,2) * (640,320)).astype(int)
    c = (np.random.rand(3)*255).astype(int)
    screen.fill("black")
    pygame.draw.lines(screen, c, True, pts, 1)
    pygame.display.flip()

def cross(x0, y0, kx, ky, w, h):
    pL = (0, y0-ky/kx*x0)
    pD = (x0-kx/ky*y0, 0)
    pR = (w, y0+ky/kx*(w-x0))
    pT = (x0+kx/ky*(h-y0), h)
    if kx>0 and ky>0:
        return pR if pR[1]<h else pT
    if kx>0 and ky<0:
        return pR if pR[1]>0  else pD
    if kx<0 and ky>0:
        return pL if pL[1]<h else pT
    if kx<0 and ky<0:
        return pL if pL[1]>0 else pD

def getNewK(kx, ky, x1, w):
    flag = x1==0 or x1==w
    return (-kx, ky) if flag else (kx, -ky)

pygame.init()
w, h = 640, 320
screen = pygame.display.set_mode((w, h))

pts = [np.random.rand(2)*(w, h)]
th = np.random.rand()*np.pi
kx, ky = np.cos(th), np.sin(th)

while True:
    if pygame.QUIT in [e.type for e in pygame.event.get()]:
        pygame.quit()
        break
    time.sleep(0.1)
    x,y = pts[-1]
    pt = cross(x,y, kx, ky, w, h)
    pts.append(pt)
    kx, ky = getNewK(kx, ky, pt[0], w)
    c = (np.random.rand(3)*255).astype(int)
    screen.fill("black")
    pygame.draw.lines(screen, c, False, pts, 1)
    pygame.display.flip()