在pygame中停止绘图时如何继续蛇头？答案

【问题标题】：How to continue with head of snake while drawing is stopped in pygame?在pygame中停止绘图时如何继续蛇头？
【发布时间】：2020-12-20 16:18:11
【问题描述】：

我有一条正在画线的蛇，并且正在随机打孔，但是当蛇没有画线（打孔）时如何继续使用头部。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，只有头部在移动，但我想让那个头部只在孔中移动。

【问题讨论】：

标签： python pygame drawing head

【解决方案1】：

如果需要绘制身体，您需要将蛇头的位置添加到列表中。清除每一帧中的显示，但绘制列表中保存的所有项目。另外，画蛇的头：

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()

【讨论】：