在2张图像之间来回切换

Question

My friend and I were bored the other day and decided to make a simple game in python. Objects fall from the top of the display window and the user must control a box to catch them before they hit the ground. We decided we would have different objects that are worth more points than others. My question is, how do you have one instance of an object falling randomly switch images.

I tried to do this myself using a variable that is a random integer between 0-10. If the integer is less than 5, the picture is set as a bat. If the integer is above 5, the picture is set as a ghost.

My attempted coding is as follows:

    #Detect if user has missed a bomb#

    bomb_img = 0
    bomb_y += vel_y
    if bomb_y > 500:
        bomb_x = random.randint(0, 500)
        bomb_y = -50
        bomb_img = random.randint(0,10)
        lives -= 1
        if lives == 0:
            game_lost = True

    #Detect if user has saved a bomb#
    elif bomb_y > pos_y:
        if bomb_x > pos_x and bomb_x < pos_x + 120:
            score += 10
            bomb_x= random.randint(0,500)
            bomb_y = -50
            bomb_img = random.randint(0,10)

    #Change bomb img#       
    ghost = pygame.image.load("ghost2.png").convert_alpha()
    bat = pygame.image.load("bat2.png").convert_alpha()
    bat_resize = pygame.transform.scale(bat, (133,95))
    if bomb_img <= 5:
        _display_window.blit(bat_resize, (bomb_x, bomb_y))
    else:
        _display_window.blit(ghost, (bomb_x, bomb_y))

However, this does not work as expected when ran. The picture does change to a ghost, but only for a split second before changing back to the bat as it continues to fall.

I also tried switching the following lines of code around:

if bomb_img <= 5:
    _display_window.blit(ghost, (bomb_x, bomb_y))
else:
    _display_window.blit(bat_resize, (bomb_x, bomb_y))

In this case the picture will randomly change to the bat for a split second, before changing back into the ghost

Basically I can get the image to change, but only for a quick second. Any thoughts?

Answer 1

It looks like the issue is that you reset bomb_img at the start of your loop, ie the first line of your code:

bomb_img = 0
...

You should pull that line outside your loop.