Very simple PyGame very slow

Question

I want to make a (a bit bigger) game in PyGame, but even with this simple code I just get arround 10 fps instead of 60? Here's the code:

import pygame

res = 1280,720
display = pygame.display.set_mode(res, pygame.RESIZABLE)
pygame.display.set_caption("Test")


background = pygame.transform.smoothscale(pygame.image.load("Background.png"), res)
a = 0
while True:
    pygame.time.Clock().tick(60)
    display.fill((0,0,0))
    a += 10

    display.blit(background, (0,0)) #Without this line: arround 20 fps

    pygame.draw.rect(display,(255,0,0), (a,8,339,205))

    pygame.display.update()

pygame.quit()

What am I doing wrong?

Thank you!

Windows 10 64bit, AMD Radeon R200 Series, 4 x 3.90GHz (AMD A8-6600K APU with Radeon(tm) HD Graphics, 16GB RAM — Frostie, Sep 15 '17 at 18:57
Try to `convert` the image: `pygame.image.load("Background.png").convert()`. Also, what size does it have? — skrx, Sep 16 '17 at 04:22
It's going better but It's not fast enough. Anyway it's 2 times slower than it should be. But thanks for your idea it helped a bit. — Frostie, Sep 16 '17 at 10:40
Try to profile your game with [cProfile](https://docs.python.org/3/library/profile.html). — skrx, Sep 16 '17 at 23:17
BTW, there seem to be [bugs in the latest pygame version](https://stackoverflow.com/questions/46160971/pygame-full-core-usage-in-simple-loop) that occupy a CPU core 100%. Maybe your problem has to do with these bugs. — skrx, Sep 16 '17 at 23:31
Also, create a clock instance above the while loop `clock = pygame.time.Clock()` and then replace the `pygame.time.Clock().tick(60)` line with `clock.tick(60)`. — skrx, Sep 16 '17 at 23:43
clock.tick(60) helped! Thank you! cProfile also helped me! Now I know how to increase my speed thank you very much! — Frostie, Sep 17 '17 at 09:41

Maximouse · Answer 1 · 2018-12-06T12:45:01.683

2

Try the following optimizations:

Use the convert() method on your image pygame.image.load("Background.png").convert()). This makes the animation about 5 times faster.
Instead of re-blitting entire background every frame, only update the changed parts of the screen.
You don't need to clear the screen before drawing the background.
Use the same Clock instance every frame.

Here's the code:

import pygame

pygame.init()
res = (1280, 720)
display = pygame.display.set_mode(res, pygame.RESIZABLE)
pygame.display.set_caption("Test")

background = pygame.transform.smoothscale(pygame.image.load(r"E:\Slike\Bing\63.jpg").convert(), res)
a = 0
clock = pygame.time.Clock()

display.blit(background, (0, 0))
pygame.display.update()
while True:
    clock.tick(60)
    rect = (a,8,339,205)
    display.blit(background, rect, rect) # draw the needed part of the background
    pygame.display.update(rect) # update the changed area
    a += 10
    rect = (a,8,339,205)
    pygame.draw.rect(display, (255,0,0), rect)
    pygame.display.update(rect) # update the changed area

edited Dec 06 '18 at 12:45

answered Dec 05 '18 at 08:54

Maximouse

4,170
1
14
28

Your first two points are valid for this specific example, but they're impossible to do in more complex games. Pygame should be fast enough to run 60fps in full screen even with multiple sprites and backgrounds with a computer like OP's. While your tips certainly help, they don't solve the root of the problem, they only lessen its effects. – Nearoo Dec 06 '18 at 08:36
Original: 20 FPS With convert(): 110 FPS Without clearing the screen: 220 FPS When only updating the changed area: clock.get_fps() returns infinity – Maximouse Dec 06 '18 at 09:43
(Now I changed my answer.) – Maximouse Dec 06 '18 at 09:55

Very simple PyGame very slow

1 Answers1