在pygame中停止绘图时，如何继续使用蛇头

Question

我有一条正在画线的蛇，它随机地在造洞，但当蛇不画(造洞(时，如何继续用头。这是我的代码：

import pygame
pygame.init()
import random
from random import randint
win = pygame.display.set_mode((1280,720))
background = pygame.Surface(win.get_size(), pygame.SRCALPHA)
background.fill((0, 0, 0, 1))
x = randint(150,1130)
y = randint(150,570)
vel = 0.6
direction = pygame.math.Vector2(vel, 0).rotate(random.randint(0, 360))
next_change_time = 0
draw_snake = False
clock = pygame.time.Clock()
run = True
while run:
clock.tick(150)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
current_time = pygame.time.get_ticks()
if current_time > next_change_time:
draw_snake = not draw_snake
if draw_snake:
next_change_time = current_time + random.randint(2000, 5000)
else:
next_change_time = current_time + random.randint(200, 500)

keys = pygame.key.get_pressed()

if keys[pygame.K_LEFT]:
direction.rotate_ip(-0.8)
if keys[pygame.K_RIGHT]:
direction.rotate_ip(0.8)
x += direction.x
y += direction.y

if draw_snake:
pygame.draw.circle(win, (255,0,0), (round(x), round(y)), 4)
pygame.display.update()
pygame.quit()

当我在while循环中写win.fill((0,0,0))时，只有磁头在移动，但我想让磁头只在孔中移动。

Answer 1

如果需要绘制身体，则需要将蛇头的位置添加到列表中。清除每帧中的显示，但绘制列表中保存的所有项目。另外，画蛇头：

snake_list = []
while run:
# [...]
x += direction.x
y += direction.y
if draw_snake:
snake_list.append((x, y))
win.fill((0,0,0))
for pos in snake_list:
pygame.draw.circle(win, (255,0,0), (round(pos[0]), round(pos[1])), 4)
pygame.draw.circle(win, (255,0,0), (round(x), round(y)), 4)
pygame.display.update()

---

完整示例：

pygame.init()
import random
from random import randint
win = pygame.display.set_mode((1280,720))
background = pygame.Surface(win.get_size(), pygame.SRCALPHA)
background.fill((0, 0, 0, 1))
x = randint(150,1130)
y = randint(150,570)
vel = 0.6
direction = pygame.math.Vector2(vel, 0).rotate(random.randint(0, 360))
next_change_time = 0
draw_snake = False
snake_list = []
clock = pygame.time.Clock()
run = True
while run:
clock.tick(150)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
current_time = pygame.time.get_ticks()
if current_time > next_change_time:
draw_snake = not draw_snake
if draw_snake:
next_change_time = current_time + random.randint(2000, 5000)
else:
next_change_time = current_time + random.randint(200, 500)

keys = pygame.key.get_pressed()

if keys[pygame.K_LEFT]:
direction.rotate_ip(-0.8)
if keys[pygame.K_RIGHT]:
direction.rotate_ip(0.8)
x += direction.x
y += direction.y
if draw_snake:
snake_list.append((x, y))
win.fill((0,0,0))
for pos in snake_list:
pygame.draw.circle(win, (255,0,0), (round(pos[0]), round(pos[1])), 4)
pygame.draw.circle(win, (255,0,0), (round(x), round(y)), 4)
pygame.display.update()
pygame.quit()