# Tk_warp_speed.py

# Tk_warp_speed.py

import math
from Tkinter import Tk, Canvas
from random import randrange

ww = 1200
hh = 600
master = Tk()
master.title("StarField")
master.resizable(False, False)
master.maxsize(ww, hh)
fov = 180 * math.pi / 180
view_distance = 0
stars = []
canvas = Canvas(master, width=ww, height=hh, bg="#000000")
canvas.pack()

class Star():
    id = None
    x = 0
    y = 0
    z = 0
    radius = 1
    fill = 0

def xy(star, width, height):
    d = 2.5
    star.x=randrange(-width*d, width*d)
    star.y=randrange(-height*d, height*d)

def StarField(width, height, max_depth=32, num_stars=500):
    for x in range(num_stars):
        star = Star()
        xy(star, width, height)
        star.z=randrange(3, max_depth)
        star.id = canvas.create_oval(star.x - star.radius, star.y - star.radius, star.x + star.radius, star.y + star.radius, fill='#FFFFFF')
        stars.append(star)

    while 1:
        canvas.delete('streaks')
        for star in stars:
            # move depth
            star.z -= 1.0
            star.radius = (1 - star.z / max_depth) * 3.0
            star.fill = int((1 - star.z / max_depth) * 255)

            # reset depth
            if star.z <= 0:
                xy(star, width, height)
                star.z=randrange(int(max_depth*0.6), max_depth)
                star.radius = 3
                star.fill = 0

            # Transforms 2D to 3D using a perspective projection
            factor = fov / (view_distance + star.z)
            x = star.x * factor + width / 2
            y = -star.y * factor + height / 2

            if star.fill:
                c = 255-star.fill
                t = star.fill**2*10
                x0, y0 = star.x*t, star.y*t
                streak = [(x0/p+ww/2, y0/p+hh/2) for p in (c*(50+c),c*(200+c))]
                line_color = '#'+('%02x'%star.fill)*3
                canvas.create_line(streak, fill=line_color, tag='streaks')
            canvas.coords(star.id, x - star.radius, y - star.radius, x + star.radius, y + star.radius)
            canvas.itemconfig(star.id, fill='#'+('%02x'%star.fill)*3)
        canvas.update()

StarField(ww, hh)