用 Python 实现一场环保无污染的烟花秀

烟花由中国古代人民较早发明，常用于盛大的典礼或表演中，也在除夕夜及元宵节中燃放用来烘托节日氛围。近年来随着环境污染的加剧，一些地区已经禁止燃放烟花了，那我们就用 Python 实现一场无污染的烟花秀。

环境

• 操作系统：Windows
• Python 版本：3.6
• 涉及模块：tkinter、PIL、time、random、math

实现

导入库

import tkinter as tk
from PIL import Image, ImageTk
from time import time, sleep
from random import choice, uniform, randint
from math import sin, cos, radians

烟花颜色

colors = ['red', 'blue', 'yellow', 'white', 'green', 'orange', 'purple', 'seagreen', 'indigo', 'cornflowerblue']

定义烟花类

class fireworks:
    def __init__(self, cv, idx, total, explosion_speed, x=0., y=0., vx=0., vy=0., size=2., color='red', lifespan=2, **kwargs):
        self.id = idx
        # 烟花绽放 x 轴
        self.x = x
        # 烟花绽放 x 轴
        self.y = y
        self.initial_speed = explosion_speed
        # 外放 x 轴速度
        self.vx = vx
        # 外放 y 轴速度
        self.vy = vy
        # 绽放的粒子数
        self.total = total
        # 已停留时间
        self.age = 0
        # 颜色
        self.color = color
        # 画布
        self.cv = cv
        self.cid = self.cv.create_oval(x - size, y - size, x + size, y + size,
        fill=self.color)
        self.lifespan = lifespan

    # 更新数据
    def update(self, dt):
        self.age += dt
        # 粒子膨胀
        if self.alive() and self.expand():
            move_x = cos(radians(self.id * 360 / self.total)) * self.initial_speed
            move_y = sin(radians(self.id * 360 / self.total)) * self.initial_speed
            self.cv.move(self.cid, move_x, move_y)
            self.vx = move_x / (float(dt) * 1000)
        # 膨胀到最大下落
        elif self.alive():
            move_x = cos(radians(self.id * 360 / self.total))
            self.cv.move(self.cid, self.vx + move_x, self.vy + 0.5 * dt)
            self.vy += 0.5 * dt
        # 过期移除
        elif self.cid is not None:
            cv.delete(self.cid)
            self.cid = None

    # 定义膨胀效果的时间帧
    def expand(self):
        return self.age <= 1.5

    # 检查粒子是否仍在生命周期内
    def alive(self):
        return self.age <= self.lifespan

燃放烟花

def ignite(cv):
    t = time()
    # 烟花列表
    explode_points = []
    wait_time = randint(10, 100)
    # 爆炸的个数
    numb_explode = randint(6, 10)
    for point in range(numb_explode):
        # 爆炸粒子列表
        objects = []
        # 爆炸 x 轴
        x_cordi = randint(50, 550)
        # 爆炸 y 轴
        y_cordi = randint(50, 150)
        speed = uniform(0.5, 1.5)
        size = uniform(0.5, 3)
        color = choice(colors)
        # 爆炸的绽放速度
        explosion_speed = uniform(0.2, 1)
        # 爆炸的粒子数半径
        total_particles = randint(10, 50)
        for i in range(1, total_particles):
            r = fireworks(cv, idx=i, total=total_particles, explosion_speed=explosion_speed, x=x_cordi, y=y_cordi,
                     vx=speed, vy=speed, color=color, size=size,
                     lifespan=uniform(0.6, 1.75))
            # 添加进粒子列表里
            objects.append(r)
        # 把粒子列表添加到烟花列表
        explode_points.append(objects)
    total_time = .0
    # 在 1.8 秒时间帧内保持更新
    while total_time < 1.8:
        # 让画面暂停 0.01s
        sleep(0.01)
        # 刷新时间
        tnew = time()
        t, dt = tnew, tnew - t
        # 遍历烟花列表
        for point in explode_points:
            # 遍历烟花里的粒子列表
            for item in point:
                # 更新时间
                item.update(dt)
        # 刷新页面
        cv.update()
        total_time += dt
    root.after(wait_time, ignite, cv)

启动

if __name__ == "__main__":
    root = tk.Tk()
    # 绘制一个画布
    cv = tk.Canvas(root, height=400, width=600)
    # 背景图
    image = Image.open("bg.jpg")
    photo = ImageTk.PhotoImage(image)
    # 在画板上绘制一张图片
    cv.create_image(0, 0, image=photo, anchor='nw')
    cv.pack()
    root.protocol(close)
    root.after(100, ignite, cv)
    # 生成窗口
    root.mainloop()

最终效果，如图所示：