如何为每个精灵分配图像？

Question

I want an image to be in the place of the rectangle.

The class Block is used to make a 'food' square, enemy square, and player square. I need help reformatting Block to also accept an image in the color attributes place.

import pygame
import random

# Define some colors
BLACK = (0,   0,   0)
WHITE = (255, 255, 255)
RED = (255,   0,   0)
BLUE = (0,0,255)
GREEN = (0,255,0)

class Block(pygame.sprite.Sprite):
    """
    This class represents the ball.
    It derives from the "Sprite" class in Pygame.
    """

    def __init__(self, color, width, height):
        """ Constructor. Pass in the color of the block,
        and its size. """

        # Call the parent class (Sprite) constructor
        super().__init__()

        # Create an image of the block, and fill it with a color.
        # This could also be an image loaded from the disk.
        self.image = pygame.Surface([width, height])
        self.image.fill(color)

        # Fetch the rectangle object that has the dimensions of the image
        # image.
        # Update the position of this object by setting the values
        # of rect.x and rect.y
        self.rect = self.image.get_rect()

class Player(pygame.sprite.Sprite):
    """ The class is the player-controlled sprite. """

    # -- Methods
    def __init__(self, x, y):
        """Constructor function"""
        # Call the parent's constructor
        super().__init__()

        # Set height, width
        self.image = pygame.Surface([15, 15])
        self.image.fill(BLUE)

        # Make our top-left corner the passed-in location.
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

        # -- Attributes
        # Set speed vector
        self.change_x = 0
        self.change_y = 0

    def changespeed(self, x, y):
        """ Change the speed of the player"""
        self.change_x += x
        self.change_y += y

    def update(self):
        """ Find a new position for the player"""
        if self.rect.x < 0:
            self.rect.x += 3
            wall.play()
        if self.rect.x > 685:
            self.rect.x-=3
            wall.play()
        if self.rect.y < 0:
            self.rect.y += 3
            wall.play()
        if self.rect.y > 384:
            self.rect.y -= 3
            wall.play()
        else:
            self.rect.x += self.change_x
            self.rect.y += self.change_y

# Initialize Pygame
pygame.init()

# Set the height and width of the screen
screen_width = 700
screen_height = 400
screen = pygame.display.set_mode([screen_width, screen_height])

# This is a list of 'sprites.' Each block in the program is
# added to this list. The list is managed by a class called 'Group.'
good_block_list = pygame.sprite.Group()

bad_block_list = pygame.sprite.Group()

collision_sound_good = pygame.mixer.Sound("good_block.wav")
collision_sound_bad = pygame.mixer.Sound("bad_block.wav")
wall = pygame.mixer.Sound("bump.wav")

# This is a list of every sprite.
# All blocks and the player block as well.
all_sprites_list = pygame.sprite.Group()

for i in range(50):
    # This represents a block
    block = Block(GREEN, 20, 15)

    # Set a random location for the block
    block.rect.x = random.randrange(screen_width)
    block.rect.y = random.randrange(screen_height)

    # Add the block to the list of objects
    good_block_list.add(block)
    all_sprites_list.add(block)

for i in range(50):
    # This represents a block
    block = Block(RED, 20, 15)

    # Set a random location for the block
    block.rect.x = random.randrange(screen_width)
    block.rect.y = random.randrange(screen_height)

    # Add the block to the list of objects
    bad_block_list.add(block)
    all_sprites_list.add(block)

# Create a RED player block
player = Player(100,50)
all_sprites_list.add(player)

# Loop until the user clicks the close button.
done = False

# Used to manage how fast the screen updates
clock = pygame.time.Clock()

score = 0

# -------- Main Program Loop -----------
while not done:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
            # Set the speed based on the key pressed
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                player.changespeed(-3, 0)
            elif event.key == pygame.K_RIGHT:
                player.changespeed(3, 0)
            elif event.key == pygame.K_UP:
                player.changespeed(0, -3)
            elif event.key == pygame.K_DOWN:
                player.changespeed(0, 3)

        # Reset speed when key goes up
        elif event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT:
                player.changespeed(3, 0)
            elif event.key == pygame.K_RIGHT:
                player.changespeed(-3, 0)
            elif event.key == pygame.K_UP:
                player.changespeed(0, 3)
            elif event.key == pygame.K_DOWN:
                player.changespeed(0, -3)

# Game Logic
    # This calls update on all the sprites

    all_sprites_list.update()
    # Clear the screen
    screen.fill(WHITE)

    good_blocks_hit_list = pygame.sprite.spritecollide(player, good_block_list, True)
    bad_blocks_hit_list = pygame.sprite.spritecollide(player, bad_block_list, True)

    # Check the list of collisions.
    for block in good_blocks_hit_list:
        collision_sound_good.play()
        score += 1
        print(score)

    for block in bad_blocks_hit_list:
        collision_sound_bad.play()
        score -= 1
        print(score)

    font = pygame.font.SysFont(None, 45)
    text = font.render(str(score), True, BLACK)
    screen.blit(text, (54, 350))

    # Draw all the spites
    all_sprites_list.draw(screen)

    # Go ahead and update the screen with what we've drawn.
    pygame.display.flip()

    # Limit to 60 frames per second
    clock.tick(60)

pygame.quit()

There are 3 different kinds of blocks that need a separate image. The blocks are added to sprite group, so I don't think it is possible to Blit the image in the loop.

Question Answered

Answer 1

I would modify the Block constructor such that the color parameter was just a parameter representing the appearance of the sprite. It might be a string filename, or a colour-tuple. This can be tested at run-time.

def __init__(self, appearance, width, height):
    """ Create a new sprite sized <width> by <height>.
        The sprite is, either a coloured block where <appearance> is a 
        RGB colour-tuple, OR an image loaded from a file """

    # Call the parent class (Sprite) constructor
    super().__init__()

    # appearance is either an RGB tuple, or a filename str
    if ( type( appearance ) is tuple ):
        # Create an image of the block, and fill it with a color
        self.image = pygame.Surface([width, height])
        self.image.fill( appearance )
    else:
        # The parameter <appearance> holds an image filename
        bitmap = pygame.image.load( appearance ).convert()
        self.image = pygame.transform.smoothscale( bitmap, ( width, height ) )

    # Fetch the rectangle object that has the dimensions of the image image.
    # Update the position of this object by setting the values
    # of rect.x and rect.y
    self.rect = self.image.get_rect()

I'm not really sure this is the best approach of doing this sort of thing. I guess maybe it could allow for a debug-fallback if the image resources are not found or suchlike.

This allows the code to:

new_sprite = Block( ( 182, 128, 0 ), 64, 64 )

[...]

new_sprite = Block( "sandstone.png", 64, 64 )

Answer 2

Soo I may have an answer for my own question...

class Block(pygame.sprite.Sprite):
    """
    This class represents the ball.
    It derives from the "Sprite" class in Pygame.
    """

    def __init__(self, imageFile, width, height):
        """ Constructor. Pass in the color of the block,
        and its size. """

        # Call the parent class (Sprite) constructor
        super().__init__()

        # Create an image of the block, and fill it with a color.
        # This could also be an image loaded from the disk.
        #self.image = pygame.Surface([width, height])
        #self.image.fill(color)
        self.image = pygame.image.load(imageFile).convert()

        # Fetch the rectangle object that has the dimensions of the image
        # image.
        # Update the position of this object by setting the values
        # of rect.x and rect.y
        self.rect = self.image.get_rect()