如何在pygame中将一个表面（图像）转换为另一个表面？

Question

How do I convert an image to another image in pygame without using sprite class? Also how can I remove the previous image after I convert it to another one?

Answer 1

Converting one image to another is as simple as reassigning the variable

firstImage = pygame.image.load("firstImage.png")
secondImage = pygame.image.load("secondImage.png")

firstImage = secondImage

del secondImage

I'm not sure what exactly you mean by removing the image. You could use "del secondImage" to delete the reference in your code and send it to garbage collection. Once you clear the screen and blit the updated image there should no longer be any sign of the outdated image.

Answer 2

I wrote a small program today that shows how I switch an objects image(it may help/answer your question). It has notes for most of the code's use so it is easier to understand how and why it works(for all I know, anyone could have started programming yesterday).

Anyway, here is the code:

import pygame, sys

#initializes pygame
pygame.init()

#sets pygame display width and height
screen = pygame.display.set_mode((600, 600))

#loads images
background = pygame.image.load("background.png").convert_alpha()

firstImage = pygame.image.load("firstImage.png").convert_alpha()

secondImage = pygame.image.load("secondImage.png").convert_alpha()

#object
class Player:
    def __init__(self):

        #add images to the object
        self.image1 = firstImage
        self.image2 = secondImage

#instance of Player
p = Player()

#variable for the image switch
image = 1

#x and y coords for the images
x = 150
y = 150

#main program loop
while True:

    #places background
    screen.blit(background, (0, 0))

    #places the image selected
    if image == 1:
        screen.blit(p.image1, (x, y))
    elif image == 2:
        screen.blit(p.image2, (x, y))

    #checks if you do something
    for event in pygame.event.get():

        #checks if that something you do is press a button
        if event.type == pygame.KEYDOWN:

            #quits program when escape key pressed
            if event.key == pygame.K_ESCAPE:
                sys.exit()

            #checks if down arrow pressed
            if event.key == pygame.K_DOWN:

                #checks which image is active
                if image == 1:

                    #switches to image not active
                    image = 2

                elif image == 2:

                    image = 1

    #updates the screen
    pygame.display.update()

I am not sure how your code is set up or if this is what you need (I don't entirely understand classes either so it might be a sprite class), but I hope this helps!