Illustrate PhotoImage pixel-plotting slowdown

tk_photoimage_pixels2.py

#!/usr/bin/env python3

''' Use a PhotoImage to plot single pixels in a Tkinter Label

    Written by PM 2Ring 2017.05.13
'''

import tkinter as tk
from time import perf_counter
import sys

class PGrid(object):
    def __init__(self, width, height):
        self.root = tk.Tk()
        self.width, self.height = width, height
        self.photo = tk.PhotoImage(width=width, height=height)
        self.label = tk.Label(self.root, bg='#000', image=self.photo)
        self.label.pack()

        self.bodies = []
        self.count = 0
        self.tick = 0
        self.oldtime = perf_counter()

    def add_body(self, body):
        self.bodies.append(body)

    def update(self):
        for body in self.bodies:
            self.photo.put(body.color, (body.x, body.y))
            body.update()
        self.show_speed(200)
        self.root.after(5, self.update)

    def start(self):
        self.update()
        self.root.mainloop()
        print()

    def show_speed(self, maxcount=100):
        self.count += 1
        if self.count == maxcount:
            newtime = perf_counter()
            rate = maxcount / (newtime - self.oldtime)
            self.oldtime = newtime
            self.count = 0
            #print('{:.2f}->{:.2f}'.format(rate, 1000 / rate), end='\t')
            print('{:.2f}'.format(rate), end='\t')
            sys.stdout.flush()

            # Test the effect of blanking the PhotoImage: it speeds back up
            # each time it gets blanked
            self.tick += 1
            if self.tick % 10 == 0:
                self.photo.blank()
                print()

class Body(object):
    def __init__(self, pgrid, x, y, dx, dy, color):
        self.pgrid = pgrid
        self.x, self.y = x, y
        self.dx, self.dy = dx, dy
        self.color = color
        pgrid.add_body(self)

    def update(self):
        self.x += self.dx
        self.y += self.dy
        if not 0 <= self.x < self.pgrid.width:
            self.dx = -self.dx
            self.x += self.dx
        if not 0 <= self.y < self.pgrid.height:
            self.dy = -self.dy
            self.y += self.dy


width, height = 407, 301
pgrid = PGrid(width, height)

Body(pgrid, 140, 5,  1, 1, '#ddffaa'),
Body(pgrid, 160, 5,  1, 1, '#ffaadd'),
Body(pgrid, 180, 5,  1, 1, '#aaddff'),

pgrid.start()