#!/usr/bin/python

-- coding:utf-8 --

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

模拟重力

GRAVITY = 0.05

颜色选项（随机或者按顺序）

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

''' particles 类

粒子在空中随机生成随机,变成一个圈、下坠、消失

属性: - id: 粒子的id - x, y: 粒子的坐标 - vx, vy: 在坐标的变化速度 - total: 总数 - age: 粒子存在的时长 - color: 颜色 - cv: 画布 - lifespan: 最高存在时长

'''

class Particle:

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
    self.x = x
    self.y = y
    self.initial_speed = explosion_speed
    self.vx = vx
    self.vy = vy
    self.total = total
    self.age = 0.1
    self.color = color
    self.cv = cv
    self.cid = self.cv.create_oval(
        x - size, y - size, x + size,
        y + size, fill=self.color)
    self.lifespan = lifespan

def update(self, dt):
    self.age += dt

    # 粒子范围扩大
    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)

    # 以自由落体坠落
    elif self.alive():
        move_x = cos(radians(self.id * 360 / self.total))
        # we technically don't need to update x, y because move will do the job
        self.cv.move(self.cid, self.vx + move_x, self.vy + GRAVITY * dt)
        self.vy += GRAVITY * dt

    # 移除超过最高时长的粒子
    elif self.cid is not None:
        cv.delete(self.cid)
        self.cid = None

# 扩大的时间
def expand (self):
    return self.age <= 2.2

# 粒子是否在最高存在时长内
def alive(self):
    return self.age <= self.lifespan

''' 循环调用保持不停 '''

def simulate(cv):

t = time()
explode_points = []
wait_time = randint(10, 100)
numb_explode = randint(6, 10)
# 创建一个所有粒子同时扩大的二维列表
for point in range(numb_explode):
    objects = []
    x_cordi = randint(50, 550)
    y_cordi = randint(50, 150)
    speed = uniform(0.5, 1.5)
    size = uniform(0.5, 3)
    color = choice(colors)
    explosion_speed = uniform(0.2, 1)
    total_particles = randint(10, 50)
    for i in range(1, total_particles):
        r = Particle(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))
        objects.append(r)
    explode_points.append(objects)

total_time = .0
# 1.8s内一直扩大
while total_time < 1.8:
    sleep(0.01)
    tnew = time()
    t, dt = tnew, tnew - t
    for point in explode_points:
        for item in point:
            item.update(dt)
    cv.update()
    total_time += dt
# 循环调用
root.after(wait_time, simulate, cv)

def close(*ignore):

"""退出程序、关闭窗口"""
global root
root.quit()

if name == 'main':

root = tk.Tk()
cv = tk.Canvas(root, height=800, width=451)
# 选一个好看的背景会让效果更惊艳!
image = Image.open(r"C:\\Users\\申振力\\Pictures\\image.jpg")
photo = ImageTk.PhotoImage(image)

cv.create_image(0, 0, image=photo, anchor='nw')
cv.pack()

root.protocol("WM_DELETE_WINDOW", close)
root.after(100, simulate, cv)
root.mainloop()