CODEWITHSUNDEEP
pythonloopspygame
tgmjack
tgmjack

Reputation: 42

Why doesn't Python perform a function each time it goes through a loop?

I've written this script which creates grey squares which move left and stop at a point, and creates red squares which go right indefinitely. Currently it only makes 1 of each square.

To my mind (I'm a begginer) the part of the script below is in a loop so each time the computer goes through the loop it should create a new grey square until there are a total of 15 squares. Why doesn't it?

(btw germans are grey squares)

if germancount<15:
    spawn_soldier(german_startx, german_starty, german_width, german_height, grey)

My full code is below:

import pygame
import time
import random


pygame.init()

display_width = 1000
display_height= 800

black = (0,0,0)
white = (255,255,255)
red = (255,0,0)
green = (0,255,0)
blue = (0,0,255)
grey=(169,169,169)

gameDisplay= pygame.display.set_mode((800,600))

pygame.display.set_caption('stalingrad')

clock = pygame.time.Clock()



def spawn_soldier(thingx,thingy, thingw, thingh, colour):
    pygame.draw.rect(gameDisplay, colour,[thingx, thingy, thingw, thingh])


def game_loop():

    russian_width= 20
    russian_height= 20
    russian_speed = 2
    russian_startx=-30
    russian_starty=random.randrange(0, display_height)

    german_width=20
    german_height=20
    german_speed=-1
    german_startx=780
    german_starty=random.randrange(0, display_height)

    germancount=0
    russiancount=0

    game_exit=False

    while not game_exit:
        gameDisplay.fill(white)



        if germancount<15:
            spawn_soldier(german_startx, german_starty, german_width, german_height, grey)

        if german_startx > 700:
            german_startx += german_speed

        if russiancount<100:
            spawn_soldier(russian_startx, russian_starty, russian_width, russian_height, red)


            russian_startx += russian_speed

        pygame.display.update()
        clock.tick(60)


game_loop()
pygame.quit()
quit()

edit, i suppose ive worked out a way of defining my problem a bit better.

i need like 15 of these "spawn_soldier" functions just for the Germans.

            spawn_soldier_1(german_startx, german_starty, german_width, 
            spawn_soldier_2(german_startx, german_starty, german_width, 
            spawn_soldier_3(german_startx, german_starty, german_width,

is there any way to get it to do 115 different versions of this function with different values for y without copy and pasting 115 times? because thats just going to be a nightmare.

Upvotes: 2

Views: 94

Answers (1)

abarnert
abarnert

Reputation: 365807

Each time through the loop, you do spawn a new soldier. In fact, because you never change germancount or russiancount, you do this not just 15 times, but forever. Each time, you erase all the existing soldiers by covering them with white, then spawn a new German and a new Russian, forever (although eventually they're off the edge of the screen so you won't see them).

I think what you want is to write a function that draws soldiers:

def draw_soldier(rect, colour):
    pygame.draw.rect(gameDisplay, colour, rect)

And then, inside your frame loop, after erasing the whole screen with a field of white snow like a winter in Stalingrad, add a new rectangle each time, and then draw all of the rectangles anew:

# When the game starts, there are no soldiers
germans = []
russians = []

while not game_exit:
    gameDisplay.fill(white)

    # Each time through the loop, add another soldier to each
    # side until they're full
    if len(germans) < germancount:
        germans.append([german_startx, german_starty, german_width, german_height])
        german_startx += german_speed
    if len(russians) < russiancount:
        russians.append([russian_startx, russian_starty, russian_width, russian_height])
        russian_startx += russian_speed

    # Now draw all the soldiers in front of that white fill
    for german in germans:
        draw_soldier(german, grey)
    for russian in russians:
        draw_soldier(russian, red)

    pygame.display.update()
    clock.tick(60)

Upvotes: 4

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