inserting image in middle of pygame scene - pygame

Question

i have one problem which i can't understand and please help me(sorry for big code), but you should be able to see whole picture
import numpy as np
import matplotlib.pyplot as plt
from pygame.locals import *
import pygame
pygame.init()
screen_width =800
screen_height =800
screen =pygame.display.set_mode((screen_width,screen_height))
pygame.display.set_caption("Platformer")
sky_img =pygame.image.load("sky.png")
sun_img =pygame.image.load("sun.png")
restart_img =pygame.image.load("restart_btn.png")
start_image =pygame.image.load("start_btn.png")
exit_image =pygame.image.load("exit_btn.png")
clock =pygame.time.Clock()
fps =60
tile_size =40
world_data = [
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 1],
[1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 2, 2, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 7, 0, 5, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 1],
[1, 7, 0, 0, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 7, 0, 0, 0, 0, 1],
[1, 0, 2, 0, 0, 7, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 2, 0, 0, 4, 0, 0, 0, 0, 3, 0, 0, 3, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 2, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 7, 0, 0, 0, 0, 2, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1],
[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 2, 2, 2, 2, 2, 1],
[1, 0, 0, 0, 0, 0, 2, 2, 2, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1],
[1, 0, 0, 0, 0, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[1, 0, 0, 0, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
]
blob_group = pygame.sprite.Group()
lava_group =pygame.sprite.Group()
game_over =0
class World():
def __init__(self,data):
self.tile_list =[]
wall_imag =pygame.image.load("dirt.png")
grass_img =pygame.image.load("grass.png")
row_count =0
for row in data:
col_count =0
for tile in row:
if tile ==1:
img =pygame.transform.scale(wall_imag,(tile_size,tile_size))
img_rect =img.get_rect()
img_rect.x =col_count*tile_size
img_rect.y =row_count*tile_size
tile =(img,img_rect)
self.tile_list.append(tile)
if tile == 2:
img = pygame.transform.scale(grass_img, (tile_size, tile_size))
img_rect = img.get_rect()
img_rect.x = col_count * tile_size
img_rect.y = row_count * tile_size
tile = (img, img_rect)
self.tile_list.append(tile)
if tile ==3:
blob =Enemy(col_count*tile_size,row_count*tile_size+15)
blob_group.add(blob)
if tile ==6:
lava =Lava(col_count*tile_size,row_count*tile_size+(tile_size)//2)
lava_group.add(lava)
col_count+=1
row_count+=1
def draw(self):
for tile in self.tile_list:
screen.blit(tile[0],tile[1])
class Button():
def __init__(self,x,y,image):
self.image =image
self.rect =self.image.get_rect()
self.x =x
self.y =y
self.clicked =False
def draw(self):
action =False
pos =pygame.mouse.get_pos()
if self.rect.collidepoint(pos):
if pygame.mouse.get_pressed()[0]==1 and self.clicked==False:
action =True
self.clicked =True
if pygame.mouse.get_pressed()[0] ==0:
self.clicked =False
screen.blit(self.image,self.rect)
return action
class Player():
def __init__(self,x,y):
self.reset(x,y)
def reset(self,x,y):
self.images_right = []
self.images_left = []
self.index = 0
self.counter = 0
for num in range(1, 5):
player_img = pygame.image.load(f'guy{num}.png')
player_img = pygame.transform.scale(player_img, (40, 80))
player_imag_Left = pygame.transform.flip(player_img, True, False)
self.images_right.append(player_img)
self.images_left.append(player_imag_Left)
self.dead_image = pygame.image.load('ghost.png')
self.image = self.images_right[self.index]
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
self.vel_y = 0
self.width = self.image.get_width()
self.height = self.image.get_height()
self.jumped = False
self.direction = 0
self.in_air =True
def update(self,game_over):
dx = 0
dy =0
walk_cooldown =5
if game_over==0:
key =pygame.key.get_pressed()
if key[pygame.K_SPACE] and self.jumped ==False and self.in_air==False:
self.vel_y =-15
self.jumped =True
if key[pygame.K_SPACE] == False:
self.jumped = False
if key[pygame.K_LEFT] ==True:
dx -=5
self.counter+=1
self.direction =-1
if key[pygame.K_RIGHT] ==True:
dx +=5
self.counter += 1
self.direction=1
if key[pygame.K_LEFT]==False and key[pygame.K_RIGHT]==False:
self.counter =0
self.index =0
if self.direction==1:
self.image =self.images_right[self.index]
if self.direction==-1:
self.image = self.images_left[self.index]
if self.counter >walk_cooldown:
self.counter =0
self.index+=1
if self.index>=len(self.images_right):
self.index =0
if self.direction==1:
self.image =self.images_right[self.index]
if self.direction==-1:
self.image = self.images_left[self.index]
self.vel_y +=1
if self.vel_y >10:
self.vel_y =10
dy +=self.vel_y
self.in_air =True
for tile in world.tile_list:
if tile[1].colliderect(self.rect.x+dx,self.rect.y,self.width,self.rect.height):
dx =0
if tile[1].colliderect(self.rect.x,self.rect.y+dy,self.width,self.height):
if self.vel_y <0:
dy =tile[1].bottom -self.rect.top
self.vel_y =0
elif self.vel_y>=0:
dy =tile[1].top -self.rect.bottom
self.vel_y=0
self.in_air =False
if pygame.sprite.spritecollide(self,blob_group,False):
game_over =-1
if pygame.sprite.spritecollide(self,lava_group,False):
game_over =-1
self.rect.x +=dx
self.rect.y +=dy
if self.rect.bottom >screen_height:
self.rect.bottom =screen_height
dy =0
elif game_over==-1:
self.image =self.dead_image
if self.rect.y >200:
self.rect.y-=5
screen.blit(self.image,self.rect)
return game_over
class Enemy(pygame.sprite.Sprite):
def __init__(self,x,y):
pygame.sprite.Sprite.__init__(self)
self.image =pygame.image.load("blob.png")
self.rect =self.image.get_rect()
self.rect.x =x
self.rect.y =y
self.move_direction =1
self.move_counter =0
def update(self):
self.rect.x +=self.move_direction
self.move_counter+=1
if abs(self.move_counter)>50:
self.move_direction *=-1
self.move_counter *=-1
pygame.draw.rect(screen,(255, 255, 255),self.rect)
class Lava(pygame.sprite.Sprite):
def __init__(self,x,y):
pygame.sprite.Sprite.__init__(self)
lava_image =pygame.image.load("lava.png")
self.image =pygame.transform.scale(lava_image,(tile_size,tile_size//2))
self.rect =self.image.get_rect()
self.rect.x =x
self.rect.y =y
world =World(world_data)
player =Player(100,screen_height-120)
restart_button =Button(screen_width//2-50,screen_height //2+100,restart_img)
start_button =Button(screen_width//2,screen_height//2,start_image)
exit_button =Button(280,280,exit_image)
def draw_grid():
for line in range(0,tile_size+1):
pygame.draw.line(screen,(255,255,255),(0,line*tile_size),(screen_width,line*tile_size))
pygame.draw.line(screen, (255, 255, 255), (line * tile_size,0), (line * tile_size,screen_height))
run =True
while run :
clock.tick(fps)
screen.blit(sky_img,(0,0))
screen.blit(sun_img, (100, 100))
#exit_button.draw()
#draw_grid()
world.draw()
start_button.draw()
if game_over == 0:
blob_group.update()
blob_group.draw(screen)
lava_group.draw(screen)
game_over = player.update(game_over)
if game_over==-1:
if restart_button.draw():
player.reset(100,screen_height-130)
game_over =0
for event in pygame.event.get():
if event.type ==pygame.QUIT:
run =False
pygame.display.update()
pygame.quit()
here is my result :
i want to put this image(start menu) in the middle of game, but i could not it(i have changed coordinates, try several experiments but no result yet), here is main part of positioning picture on image :
start_button =Button(screen_width//2,screen_height//2,start_image)
i have tried different numbers(starting from (0,0) and so on) but no result, i did not get what is the wrong? game is running without any problem
UPDATED
After updating my code according answer, buttons coordinate are
start_button = Button(screen_width // 2 - 350, screen_height // 2, start_image)
exit_button = Button(screen_width // 2 + 150, screen_height // 2, exit_image)
and image is `

Answer 1

The button is drawn at the location stored in the `rect attribute:
screen.blit(self.image,self.rect)
Therefore you need to set the position of the rect attribute:
class Button():
def __init__(self,x,y,image):
self.image = image
self.rect = self.image.get_rect(center = (x, y))
# [...]
You don't need the x and y attributes at all. You can delete them. The top left position of the button is (self.rect.x, self.rect.y). See also pygame.Rect.