In this chapter, we're making our game's background move to create the illusion of a continuous, scrolling scene. Here's a simple breakdown:

Move the Background

• bg_x1 -= bg_move and bg_x2 -= bg_move shift both instances of the background image to the left. This movement is determined by the value of bg_move, making it seem like the player is moving forward in the game.

Loop the Background

• The if statements check if either background image has moved entirely off the screen to the left. If bg_x1 < -bg.get_width(), it means the first background image has scrolled past the left edge of the screen. We then set bg_x1 = bg.get_width(), which moves it directly to the right of the visible screen, ready to scroll again. The same logic applies to bg_x2.

Display the Background

• main_display.blit(bg, (bg_x1, 0)) and main_display.blit(bg, (bg_x2, 0)) draw the background images on the screen at their new positions. The (bg_x1, 0) and (bg_x2, 0) specify the positions of the backgrounds. The 0 in both commands keeps the vertical position the same, ensuring the background scrolls horizontally.

By continuously moving and looping the background images like this, we create a seamless, scrolling effect that adds depth and movement to the game, making it more engaging and visually appealing.