Pygame moving object /image repeat itself

Question

I'am building a simple game using pygame ,the function of this game is to control an image and make it move up/down left/right but i got this problem, the image repeats itself when moving down or aside

import pygame
pygame.init()
display_width = 1080
display_height = 1080

screen = pygame.display.set_mode((display_width,display_height))

Clock = pygame.time.Clock()
pygame.display.set_caption('DEMO')
black=(0,0,0)
white=(255,255,255)
red=(255,0,0)
green=(0,255,0)
blue=(0,0,255)
screen.fill(white)

face=pygame.image.load('H:\\brain.jpg')

 def brain(x,y):
     screen.blit(face,(x,y))

 x1 =(display_width*0.5)
 y1 =(display_height*0.5)
  x_change =0
   y_change =0
  gameExit = False

while not gameExit:
for event in pygame.event.get():

    if event.type == pygame.QUIT:
        gameExit = True

    if event.type == pygame.KEYDOWN:
        if event.key == pygame.K_LEFT:
            x_change = -5
        elif  event.key == pygame.K_RIGHT:
            x_change = 5
        elif event.key == pygame.K_DOWN:
            y_change = 5
        elif event.key == pygame.K_UP:
            y_change = -5
    if event.type == pygame.KEYUP:
        if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
            x_change = 0
    if event.type == pygame.KEYUP:
        if event.key == pygame.K_DOWN or event.key == pygame.K_UP:
            y_change = 0

x1 += x_change
y1 += y_change
print(event)
brain(x1,y1)
pygame.display.update()
Clock.tick(100)
pygame.quit()
quit()

score 3 · Accepted Answer · answered Jun 26 '17 at 23:17

You have to blit your background at every iteration of the while-loop:

 while True:
     for event in pygame.event.get():

         #get keyboard input


     screen.fill((255, 255, 255)) #or, you can draw a background image

     x1 += x_change
     y1 += y_change
     print(event)
     brain(x1,y1)
     pygame.display.update()

score 0 · Answer 2 · answered Jun 26 '17 at 23:15

You need to blank out the old image, as well as drawing the new one. What you see is the residue: the portion of the previous images that wasn't covered by the white (background color) of the new image.

One easy way to handle this is to expand your drawn image to include a white border at least as large as the size of the motion.

Pygame moving object /image repeat itself

2 Answers2