Re: [pygame] is there a way to optimize this code?

[<don@xxxxxxxxxxxxxxxxx>]

Hi

Note that  didn't run any tests/profiling (no pygame installed on this machine).
Anyway, here are my suggestions:
1) in "init()" instead of setting pixel per pixel to green use "pygame.draw.line()"
2) in "snowfall()" you check every pixel on every frame. this is most likly your bottleneck.
   what I would do ist have a list with the positions of all snowflakes so you know exactly
   where they are and don't have search the whole screen for them (especially if you only 
   have 8). This should greatly increase performance (instead of 640*480 iterations you only 
   need 8). 

After 2) you probably won't need the optimizations you implemented.
Always remember "The Zen of Python". In this case: "Beautiful is better than ugly" and 
"Readability counts"!


regards
//Lorenz



On Mon, 17 Aug 2009 02:33:30 -0400, Victor Noagbodji <noagbodjivictor@xxxxxxxxx> wrote:
> hi, i'm following SDL tutorial here, http://sol.gfxile.net/gp/ch04.html
> 
> this is the pygame equivalent. as you can see the code is not nice
> looking. that's because i have tried all the optimization tricks i
> know (local names, avoid dot operators, numpy array etc...) the result
> is still awfully slow
> 
> help.
> 
> import numpy
> import random
> from sys import exit
> from math import sin, cos
> 
> import pygame
> import pygame.event as event
> import pygame.display as display
> 
> from pygame.locals import *
> from pygame import Surface
> from pygame.time import get_ticks
> from pygame.surfarray import pixels2d, blit_array, make_surface
> 
> WIDTH = 640
> HEIGHT = 480
> RESOLUTION = (WIDTH, HEIGHT)
> 
> def init(width, height, screen_array, green=int(0x007f00)):
>   for i in xrange(width):
>     sins = (sin((i + 3247) * 0.02) * 0.3 +
>             sin((i + 2347) * 0.04) * 0.1 +
>             sin((i + 4378) * 0.01) * 0.6)
>     p = int(sins * 100 + 380)
>     for j in range(p, height):
>       screen_array[i, j] = green
> 
> def newsnow(width, height, screen_array, white=int(0xffffff)):
>   for i in xrange(8):
>     screen_array[random.randint(1, 638), 0] = white
> 
> def snowfall(width, height, screen_array, white=int(0xffffff), black=0):
>   for j in xrange(height-2, -1, -1):
>     for i in xrange(1, width-1):
>       if screen_array[i, j] == white:
>         if screen_array[i, j+1] == black:
>           screen_array[i, j+1] = white
>           screen_array[i, j] = black
> 
> def main():
>   pygame.init()
> 
>   width = WIDTH
>   height = HEIGHT
> 
>   screen_surf = display.set_mode(RESOLUTION)
>   screen_rect = screen_surf.get_rect()
>   screen_array = pixels2d(screen_surf)
> 
>   init(width, height, screen_array)
> 
>   white = int(0xffffff)
>   black = 0
> 
>   display.update(screen_rect)
> 
>   while True:
>     tick = get_ticks()
> 
>     newsnow(width, height, screen_array)
>     #snowfall(width, height, screen_array)
> 
>     for j in xrange(height-2, -1, -1):
>       for i in xrange(1, width-1):
>         if screen_array[i, j] == white:
>           if screen_array[i, j+1] == black:
>             screen_array[i, j+1] = white
>             screen_array[i, j] = black
> 
>     display.update(screen_rect)
> 
>     for e in event.get():
>       type = e.type
>       if type == QUIT:
>         exit()
>       elif type == KEYUP and e.key == K_ESCAPE:
>         return
> 
> if __name__ == '__main__': main()
> 
> --
> paul victor noagbodji