# Tk_parallel_pixel_multiprocessing2.py

# Tk_parallel_pixel_multiprocessing2.py -- fastest in Python said to bypass GIL, especially when compiled... but maybe still much slower than a C variant.

from Tkinter import *

import time
import random
from PIL import Image, ImageTk

from multiprocessing import Pool, cpu_count

root = Tk()
root.title("Y-Axis-Parallel_Pixels")
root.geometry("120x120")
wi = 120
he = 120
w = Canvas(root, width=wi, height=he)
w.pack()

def thread_process(y):
    return [(0,random.randrange(y*2+15, 255),0) for x in range(wi)]

if __name__ == '__main__':
    pool = Pool(processes=cpu_count())
    img = Image.new( 'RGB', (wi,he))
    while 1:
        data = []
        for y in range(he):
            p = pool.map_async(thread_process, (y,))
            data.extend(p.get()[0])
        img.putdata(data)
        imgTk = ImageTk.PhotoImage(img)

        ### saw no glitches
        #time.sleep(0.02)

        w.create_image(0, 0, anchor=NW, image=imgTk)
        root.update()