'''
FIREWORKS SIMULATION WITH TKINTER
*self-containing code
*to run: simply type python simple.py in your console
*compatible with both Python 2 and Python 3
*Dependencies: tkinter, Pillow (only for background image)
*The design is based on high school physics, with some small twists only for aesthetics purpose
 
import tkinter as tk
#from tkinter import messagebox
#from tkinter import PhotoImage
from PIL import Image, ImageTk
from time import time, sleep
from random import choice, uniform, randint
from math import sin, cos, radians
# gravity, act as our constant g, you can experiment by changing it
GRAVITY = 0.05
# list of color, can choose randomly or use as a queue (FIFO)
colors = ['red', 'blue', 'yellow', 'white', 'green', 'orange', 'purple', 'seagreen','indigo', 'cornflowerblue']
Generic class for particles
particles are emitted almost randomly on the sky, forming a round of circle (a star) before falling and getting removed
from canvas
Attributes:
 - id: identifier of a particular particle in a star
 - x, y: x,y-coordinate of a star (point of explosion)
 - vx, vy: speed of particle in x, y coordinate
 - total: total number of particle in a star
 - age: how long has the particle last on canvas
 - color: self-explantory
 - cv: canvas
 - lifespan: how long a particle will last on canvas
class part:
 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
  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
  # particle expansions
  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)
  # falling down in projectile motion
  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
  # remove article if it is over the lifespan
  elif self.cid is not None:
   cv.delete(self.cid)
   self.cid = None
 # define time frame for expansion
 def expand (self):
  return self.age <= 1.2
 # check if particle is still alive in lifespan
 def alive(self):
  return self.age <= self.lifespan
Firework simulation loop:
Recursively call to repeatedly emit new fireworks on canvas
a list of list (list of stars, each of which is a list of particles)
is created and drawn on canvas at every call, 
via update protocol inside each 'part' object 
def simulate(cv):
 t = time()
 explode_points = []
 wait_time = randint(10,100)
 numb_explode = randint(6,10)
 # create list of list of all particles in all simultaneous explosion
 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 = part(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
 # keeps undate within a timeframe of 1.8 second
 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
 # recursive call to continue adding new explosion on canvas
 root.after(wait_time, simulate, cv)
def close(*ignore):
 """Stops simulation loop and closes the window."""
 global root
 root.quit()
 
if __name__ == '__main__':
 root = tk.Tk()
 cv = tk.Canvas(root, height=600, width=600)
 # use a nice background image
 image = Image.open("./image1.jpg")#背景照片路徑自行選擇，可以選擇酷炫一點(diǎn)的，看起來效果會(huì)#更好
 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()