Pygame: Cell Physics

I'm making a dumbed down version of agar.io. Currently, the cell is placed upon a grid background like in the game. The cell eats food, but only a smaller square section inside the

Solution 1:

You will need to move the .draw call to after the call to blit your background else it will cover your player's circle. I use a boolean flag here which you could then use with a timer to toggle whenever you want the split to turn off:

import pygame, sys, random
from pygame.localsimport *

# set up pygame
pygame.init()
mainClock = pygame.time.Clock()

# set up the window
width = 800
height = 600
thesurface = pygame.display.set_mode((width, height), 0, 32)
pygame.display.set_caption('')

bg = pygame.image.load("bg.png")
basicFont = pygame.font.SysFont('calibri', 36)

# set up the colors
BLACK = (0, 0, 0)
GREEN = (0, 255, 0)
WHITE = (255, 255, 255)
BLUE = (0, 0, 255)
size = 10
playercolor = BLUE
# set up the player and food data structure
foodCounter = 0
NEWFOOD = 35
FOODSIZE = 10
splitting = False
player = pygame.draw.circle(thesurface, playercolor, (60, 250), 40)
foods = []
for i inrange(20):
    foods.append(pygame.Rect(random.randint(0, width - FOODSIZE), random.randint(0, height - FOODSIZE), FOODSIZE, FOODSIZE))

# set up movement variables
moveLeft = False
moveRight = False
moveUp = False
moveDown = False

MOVESPEED = 10

score = 0# run the game loopwhileTrue:
    # check for eventsfor event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == KEYDOWN:
            # change the keyboard variablesif event.key == K_LEFT or event.key == ord('a'):
                moveRight = False
                moveLeft = Trueif event.key == K_RIGHT or event.key == ord('d'):
                moveLeft = False
                moveRight = Trueif event.key == K_UP or event.key == ord('w'):
                moveDown = False
                moveUp = Trueif event.key == K_DOWN or event.key == ord('s'):
                moveUp = False
                moveDown = Trueif event.key == K_SPACE and size >= 30: # XXX if size and space set splitting to true
                splitting = Trueif event.type == KEYUP:
            if event.key == K_ESCAPE:
                pygame.quit()
                sys.exit()
            if event.key == K_LEFT or event.key == ord('a'):
                moveLeft = Falseif event.key == K_RIGHT or event.key == ord('d'):
                moveRight = Falseif event.key == K_UP or event.key == ord('w'):
                moveUp = Falseif event.key == K_DOWN or event.key == ord('s'):
                moveDown = Falseif event.key == ord('x'):
                player.top = random.randint(0, height - player.height)
                player.left = random.randint(0, width - player.width)

        if event.type == MOUSEBUTTONUP:
            foods.append(pygame.Rect(event.pos[0], event.pos[1], FOODSIZE, FOODSIZE))

    foodCounter += 1if foodCounter >= NEWFOOD:
        # add new food
        foodCounter = 0
        foods.append(pygame.Rect(random.randint(0, width - FOODSIZE), random.randint(0, height - FOODSIZE), FOODSIZE, FOODSIZE))
    if100>score>50:
        MOVESPEED = 9elif150>score>100:
        MOVESPEED = 8elif250>score>150:
        MOVESPEED = 6elif400>score>250:
        MOVESPEED = 5elif600>score>400:
        MOVESPEED = 3elif800>score>600:
        MOVESPEED = 2elif score>800:
        MOVESPEED = 1# move the playerif moveDown and player.bottom < height:
        player.top += MOVESPEED
    if moveUp and player.top > 0:
        player.top -= MOVESPEED
    if moveLeft and player.left > 0:
        player.left -= MOVESPEED
    if moveRight and player.right < width:
        player.right += MOVESPEED
    thesurface.blit(bg, (0, 0))

    # draw the player onto the surfaceifnot splitting: # XXX check the split flag and draw accordingly...
        pygame.draw.circle(thesurface, playercolor, player.center, size)
    else:
        pygame.draw.circle(thesurface, playercolor,(player.centerx,player.centery),int(size/2))
        pygame.draw.circle(thesurface, playercolor,(player.centerx+size,player.centery+size),int(size/2))
    # check if the player has intersected with any food squares.for food in foods[:]:
        if player.colliderect(food):
            foods.remove(food)
            size+=1
            score+=1# draw the foodfor i inrange(len(foods)):
        pygame.draw.rect(thesurface, GREEN, foods[i])

    printscore = basicFont.render("Score: %d" % score, True, (0,0,0))
    thesurface.blit(printscore, (495, 10))

    pygame.display.update()
    # draw the window onto the thesurface
    pygame.display.update()
    mainClock.tick(80)

You will definitely want to make this into a few functions and/or classes too.