如何使用Pyxel与Python实现场景切换时重置计时器

问题根源 #

现有代码存在三个核心问题：

1. 场景状态混淆：用self.timer布尔值同时控制计时状态和场景切换，按下方向键后self.timer被设为False，导致escape()函数直接进入成功分支，跳过新场景显示
2. 计时器未重置：场景切换时没有重新设置self.start的时间戳，计时器会沿用初始时间，不会重新开始倒计时
3. 绘制逻辑混乱：在draw()里直接调用escape()，会重复执行清屏和绘制，逻辑嵌套导致场景切换判断失效

修复后的完整代码 #

import time
import pyxel

class App:
    def __init__(self):
        pyxel.init(250, 150, display_scale=3, title='Kingsforth')
        # 用场景名称跟踪当前位置，替代原来的timer布尔值
        self.current_scene = 'guard_room'
        # 初始化计时器起始时间
        self.start_timer()
        pyxel.run(self.update, self.draw)

    def start_timer(self):
        # 封装计时器重置逻辑，方便调用
        self.start = time.time()
        self.time_left = 5

    def update(self):
        # 实时计算剩余时间
        self.time_left = 5 - int(time.time() - self.start)
        
        # 根据当前场景处理输入
        if self.time_left >= 0:
            if (pyxel.btnp(pyxel.KEY_LEFT) or pyxel.btnp(pyxel.KEY_RIGHT) or pyxel.btnp(pyxel.KEY_UP)):
                # 切换场景并重置计时器
                if self.current_scene == 'guard_room':
                    self.current_scene = 'junk_yard'
                    self.start_timer()
                elif self.current_scene == 'junk_yard':
                    # 这里可以继续扩展下一个场景，或者设置为成功状态
                    self.current_scene = 'success'

    def draw(self):
        pyxel.cls(pyxel.COLOR_BLACK)
        
        # 守卫房间场景
        if self.current_scene == 'guard_room':
            if self.time_left >= 0:
                pyxel.text(1, 1, 'You walk into an opening filled with guards! Where do you go?', pyxel.COLOR_WHITE)
                pyxel.text(1, 10, 'Options:', pyxel.COLOR_WHITE)
                pyxel.text(35, 10, 'Left, Right, Up', pyxel.COLOR_GREEN)
                pyxel.text(1, 20, 'Time left:', pyxel.COLOR_WHITE)
                pyxel.text(45, 20, str(self.time_left), pyxel.COLOR_RED)
            else:
                pyxel.text(1, 1, 'The guards catch you. They execute you on the spot.. You die.', pyxel.COLOR_WHITE)
        
        # 垃圾场场景
        elif self.current_scene == 'junk_yard':
            if self.time_left >= 0:
                pyxel.text(1, 1, 'You run into junk yard filled with debris.. Where do you go?', pyxel.COLOR_WHITE)
                pyxel.text(1, 10, 'Options:', pyxel.COLOR_WHITE)
                pyxel.text(35, 10, 'Left, Right, Up', pyxel.COLOR_GREEN)
                pyxel.text(1, 20, 'Time left:', pyxel.COLOR_WHITE)
                pyxel.text(45, 20, str(self.time_left), pyxel.COLOR_RED)
            else:
                pyxel.text(1, 1, 'The guards catch you. They execute you on the spot.. You die.', pyxel.COLOR_WHITE)
        
        # 成功场景
        elif self.current_scene == 'success':
            pyxel.text(1, 1, 'You did it!', pyxel.COLOR_WHITE)

App()

核心修复点说明 #

• 场景状态管理：新增current_scene变量，用字符串明确标识当前场景，避免和计时状态混淆
• 计时器重置封装：把重置计时器的逻辑封装成start_timer()方法，每次切换场景时调用，确保倒计时重新开始
• 输入处理优化：用pyxel.btnp()替代pyxel.btn()，避免按住按键时连续触发场景切换
• 绘制逻辑拆分：每个场景的绘制逻辑独立，避免嵌套调用导致的混乱

内容的提问来源于stack exchange，提问作者Viul