How do I make this game properly fullscreen?

Question

import random
from time import sleep

import pygame


class InlineOverdrive:
    def __init__(self):

        pygame.init()
        self.display_width = 600
        self.display_height = 600
        self.black = (0, 0, 0)
        self.white = (255, 255, 255)
        self.clock = pygame.time.Clock()
        self.gameDisplay = None

        self.initialize()

    def initialize(self):

        self.crash = False

        self.carImg = pygame.image.load('.\\img\\Car.png')
        self.car_x_coordinate = (self.display_width * 0.45)
        self.car_y_coordinate = (self.display_height * 0.8)
        self.car_width = 49


        # Background
        self.bgImg = pygame.image.load(".\\img\\Background.png")
        rect = self.bgImg.get_rect ()
        self.bg_x2 = 0
        self.bg_y2 = -600
        self.bg_x1 = 0
        self.bg_y1 = 0

        self.bg_speed = 3
        self.count = 0

    def car(self, car_x_coordinate, car_y_coordinate):
        self.gameDisplay.blit(self.carImg, (car_x_coordinate, car_y_coordinate))

    def racing_window(self):
        self.gameDisplay = pygame.display.set_mode((self.display_width, self.display_height))
        pygame.display.set_caption('Inline Overdrive')
        self.run_car()

    def run_car(self):

        while not self.crash:

            for event in pygame.event.get():
                self.backgroundroad()
                if event.type == pygame.QUIT:
                    self.crash = True
                # print(event)

                if (event.type == pygame.KEYDOWN):
                    if (event.key == pygame.K_LEFT):
                        self.car_x_coordinate -= 50
                        print ("CAR X COORDINATES: %s" % self.car_x_coordinate)
                    if (event.key == pygame.K_RIGHT):
                        self.car_x_coordinate += 50
                        print ("CAR X COORDINATES: %s" % self.car_x_coordinate)
                    print ("x: {x}, y: {y}".format(x=self.car_x_coordinate, y=self.car_y_coordinate))

            self.gameDisplay.fill(self.black)
            self.backgroundroad()
            self.car(self.car_x_coordinate, self.car_y_coordinate)
            self.highscore(self.count)
            self.count += 1
            if (self.count % 100 == 0):
                self.bg_speed += 1

            if self.car_x_coordinate < 100 or self.car_x_coordinate > 360:
                self.crash = True
                self.display_message("You Have Crashed!")

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

    def display_message(self, msg):
        font = pygame.font.SysFont("NFS_by_JLTV.ttf", 72, True)
        text = font.render(msg, True, (255, 255, 255))
        self.gameDisplay.blit(text, (400 - text.get_width() // 2, 240 - text.get_height() // 2))
        pygame.display.update()
        self.clock.tick(60)
        sleep(1)
        inline_overdrive.initialize()
        inline_overdrive.racing_window()

    def backgroundroad(self):
        self.gameDisplay.blit(self.bgImg, (self.bg_x1, self.bg_y1))
        self.gameDisplay.blit(self.bgImg, (self.bg_x2, self.bg_y2))
        self.bg_y1 += self.bg_speed
        self.bg_y2 += self.bg_speed

        if self.bg_y1 >= self.display_height:
            self.bg_y1 = 0
        elif self.bg_y2 >= self.display_height:
            self.bg_y2 = 0

    def highscore(self, count):
        font = pygame.font.SysFont("NFS_by_JLTV.ttf", 20)
        text = font.render("SCORE : " + str(count), True, self.white)
        self.gameDisplay.blit(text, (0, 0))


if __name__ == '__main__':
    inline_overdrive = InlineOverdrive()
    inline_overdrive.racing_window()

I want this code to be able to loop the background infinitely as it moves along with the player. The screen currently does not scroll properly. The crash text is also not centered. How can I center it? If I can get my background to work properly, then my game is mostly complete. My car is also off screen for some reason. What needs to be done to make it be on the screen in the background?Image of My Car and Image of My Background

Answer 1

To center text on screen (or on any other Surface()) you can use Rect().center and

text_rect.center = display_rect.center  # center on screen

text_rect.center = button_rect.center   # center on button

font.render gives Surface(), and it has .get_rect() to get Rect() with its size and position - at start it may have position (0,0) but self.gameDisplay is also a Surface() and it has .get_rect() which gives Rect() with its size and position. If you copy .center from display to text_rect then you will have centered rect and you can use it in blit() to center text

    def display_message(self, msg):
        font = pygame.font.SysFont("NFS_by_JLTV.ttf", 72, True)
        
        text_image = font.render(msg, True, (255, 255, 255))
        text_rect = text_image.get_rect()
        
        text_rect.center = self.gameDisplay.get_rect().center
        
        self.gameDisplay.blit(text_image, text_rect)

        # ... rest ...

---

As for background mistake is self.bg_y1 = 0 and self.bg_y2 = 0 because you have to set -600 to put background above visible area.

        if self.bg_y1 >= self.display_height:
            self.bg_y1 = -600
            
        elif self.bg_y2 >= self.display_height:
            self.bg_y2 = -600

Maybe it would be simpler if you would use Rect() which has .top and .bottom

and you could set as start

        self.display_rect = self.gameDisplay.get_rect()

        self.bg2_rect.bottom = self.display_rect.top

        self.bg1_rect.bottom = self.display_rect.bottom

and later

        if self.bg1_rect.top >= self.display_rect.bottom:
            self.bg1_rect.bottom = self.display_rect.top
            
        elif self.bg2_rect.top >= self.display_rect.bottom:
            self.bg2_rect.bottom = self.display_rect.top

---

BTW:

Rect() has also .left, .right, .centerx, .centery, etc. It has also functions to detect collisions with point (ie. mouse position) - ie. rect.collidepoint(mouse_pos) - or with other rectange - ie. car_rect.colliderect( obstacle_rect )